Bash Arithmetic Expressions Interview Question:

What is the output of this program?
#!/bin/bash
echo "Which file do you want to check"
read x
until [ -e $x ]
do
echo "The file does not exist. Do you want to create? y/n"
read a
if [ $a = y ]; then
touch $x
echo "Your file has been created successfully."
fi
done
echo "The file is present in this directory"
exit 0

a) it checks the existance of your entered file in the present working directory
b) it creates the file if file does not exists
c) program runs untill you create the file
d) all of the mentioned