Python Help needed!

[Thomas]

I have this quiz game I am making and it always says 'Incorrect' when I put in the answer.
It runs with functions and files.

import random
repeat = 'True'
questionNumber = 1

def questions():
    questionList = [0,6]

    questionQuestion = random.choice(questionList)
    intOfQuestion = int(questionQuestion)

    file = open('questions')
    content = file.readlines()

    #question/answer values
    question = content[intOfQuestion]
    answerA = content[intOfQuestion + 1]
    answerB = content[intOfQuestion + 2]
    answerC = content[intOfQuestion + 3]
    answerD = content[intOfQuestion + 4]
    correctAnswer = content[intOfQuestion + 5]

    #print questions
    print('''Question {}:
{}
A = {}
B = {}
C = {}
D = {}'''.format(questionNumber, question, answerA, answerB, answerC, answerD))

    userAnswer = input("What's the answer? ").upper()
    if userAnswer == correctAnswer:
        print("Correct")
    else:
        print("Incorrect.")

def quiz():
    print()
    print("Hello and welcome to the Quiz!")

    questions()

def questionsCreate():
    q = input("Enter a question: ")
    a = input("Enter answer A: ")
    b = input("Enter answer B: ")
    c = input("Enter answer C: ")
    d = input("Enter answer D: ")
    correct = input("Enter the correct answer letter: ")

    with open("questions", "a") as a_file:
          a_file.write(str(q))
          a_file.write("\n")
          a_file.write(str(a))
          a_file.write("\n")
          a_file.write(str(b))
          a_file.write("\n")
          a_file.write(str(c))
          a_file.write("\n")
          a_file.write(str(d))
          a_file.write("\n")
          a_file.write(str(correct.upper()))
          a_file.write("\n")

def start():
    user = input("Enter your username: ")
    #need to add checker here

    quiz()
    

def create():
    #get username
        new_username = input("Enter your username to be created: ")

        #check for username in file
        usernames = open("username", "r")
        index = 0
        flag = 0

        #looping through file
        for line in usernames: 
            index += 1
          
            # checking string is present in line or not
            if new_username in line:
            
                flag = 1
                break

        #output
        if flag == 1:
            print('Username "{}" already exists or is not valid.'.format(new_username))
        else:
            #write to file
            with open("username", "a") as a_file:
                  a_file.write(new_username)
                  a_file.write("\n")
                  a_file.write('0')
                  a_file.write("\n")

                #success
                  print("The username '{}' has been created.".format(new_username))

def check():
    #get username
    check_username = input("Enter a username to check: ")

    #check for username in file
    usernames = open("username", "r")
    index = 0
    flag = 0

    #looping through file
    for line in usernames: 
        index += 1
      
        # checking string is present in line or not
        if check_username in line:
        
            flag = 1
            break

    #output
    if flag == 1:
        print('Username "{}" found.'.format(check_username))
    else:
        print('Username "{}" not found.'.format(check_username))

def developer():
    print('''[1]: Create Questions
[2]: Clear Usernames and Scores
[3]: Get Usernames''')
    developerGo = input("Where would you like to go? ")

     #where to go
    if developerGo == '1':
        questionsCreate()
    elif developerGo == '2':
        clear()
    elif developerGo== '3':
        listUsers()

def menu():
    #menu
    print('''[1]: Start Quiz
[2]: Create Username
[3]: Check Username
[4]: Developer mode''')
    toGo = input("Where would you like to go? ")
    
    #where to go
    if toGo == '1':
        start()
    elif toGo == '2':
        create()
    elif toGo == '3':
        check()
    elif toGo == '4':
        developer()
    else:
        print("Sorry I don't understand.")
        print()

menu()