if a choice is given to you, ~ 가 맞지 않나요?if you were given a choice는 문법상 어떤 부분이 적용되서 이런 표현이 가능하게 된건지 궁금합니다.
"If you were given a choice" makes more sense because "you" are the one who is gonna make a choice. You could also say "If you could chose"