I need to run the same line again in a for loop

So basically, I need to make a sort of sorting hat for a school project to see which study would best suit you. But whenever you give an invalid answer e.g. uncapitalized. It won't give you the points and goes to the next question. But I want it to give the same question again until a correct answer is given. Is this possible? It's pretty sad but I am forced to use the for loop to keep giving the question, otherwise I would have done it differently. Code:

import time
def vragen_ophalen():
    with open("C:\\Users\digit\PycharmProjects\pythonProject2\TXT\meerkeuzevragen.txt", "r") as fh:
        all_lines = fh.read()

    return all_lines;


def vraag_en_antwoord(q_a):
    se = 0  # Points for Software Engineer
    bdam = 0  # Points for Business DataManagement
    interactie = 0  # Points for Interaction Technology
    fict = 0  # Points for CSI ICT
    antwoorden = " "  # All Answers together for writing data
    vraagenantwoorden = ""  # All answers including Question No.
    vraagnummer = 1  # Question No.

    for line in q_a.split('#'):
        print(line)
        antwoord = input("Kies uit A, B, C of D: \n")
        if antwoord == "A":  # If the input given == "A" 1 point will be added to SE
            se = se + 1
        elif antwoord == "B":  # If the input given == "B" 1 point will be added to BDAM
            bdam = bdam + 1
        elif antwoord == "C":  # If the input given == "C" 1 point wil be added to Interaction Technology
            interactie = interactie + 1
        elif antwoord == "D":   # If the input given == "D" 1 point will be added to CSI ICT
            fict = fict + 1
        else:
            print("Antwoord niet mogelijk. Let op Hoofdletters!")  # Answer Not possible

        vraagenantwoord = f"{vraagnummer}. {antwoord}"  # Combining Question No. With answer
        vraagnummer = vraagnummer + 1  # Adding 1 to Question No. For next question
        vraagenantwoorden = f"{vraagenantwoorden} \n {vraagenantwoord}"  # Adds alls question and their Quesiton No. together
        with open("TXT\\antwoorden_gebruiker.txt", "w") as fd:
            fd.write(vraagenantwoorden)  # Writes all Answer and Question No. to TXT file
    main()

def main():
    run = input("Kies 1 voor Vragenlijst \n Kies 2 voor resultaten \n Kies q voor afsluiten \n")
    if run == "1":
        vraag = vragen_ophalen()
        vraag_en_antwoord(vraag)
    elif run == "2":
        with open("TXT\\antwoorden_gebruiker.txt", "r") as fr:
            print(fr.read())
    elif run == "q":
        exit()
    else:
        print("Onbekend Commando.")
        print("Herstarten in 5 seconden")
        time.sleep(5)
        main()



if __name__ == '__main__':
    main()