How to compare two files interactively using sed and looping

We want to compare file1 (questions) to file2 (answers).

File1:

1
2
3

File2:

1
2
3

Ask user: does "1" (from file1 line1) equal "1" (from file2 line1) ?

User types YES or NO and gets the answer right if it was correct. If correct then add +1 to correct answers and then display amount of correct answers.

We are looking to do this for up to 10 questions/answers...

Here is an example of where we are at so far:

#!/bin/bash
clear

#constant
score=0
file1=file1.txt
file2=file2.txt

#welcome message
echo
echo
echo "Welcome to Lab 4.2 Script Quiz!"
echo "Here you will be asked questions and must provide the correct answer..."
echo
echo

# loop

i=0
while [[ i -le 10 ]]
do

#parse files for question and answer
question='sed -n $i{p} $file1'
answer='sed -n $i{p} $file2'

#print question and answer to user
echo "Is $question"
echo "The same as $answer?"

#read user choice

read -p "- Your response: (YES or NO) " user_choice

#compare user choice against solution and increment score if correct

if [ "$user_choice" == [ "$question" == "$answer" ]
then
    score=$(( ++score ))
    echo "Correct answer, you have $score correct so far"
    i=++i
else
    echo "Wrong answer, correct answer is $answer"
    i=++i
fi

done

echo "your score is: $score out of 10 correct"

We are using an existing script ( https://github.com/h4k1m0u/bash-quiz/blob/master/bash-quiz.sh ) and trying to modify it to our needs but are stuck...

We need the sed command to echo out a result for our user to compare but it just echos the full command

After the sed command echo out a result we need an if loop to check user response to YES or NO and to compare if the user response is correct...