It's "ㄹ 거예요". 거 (=것) is a noun and you use either "이에요" or "예요" after the NOUNS. "예요" is a condensed version of "이에요" and it's used after the nouns that end with VOWELS because it's easier to say 거예요 than 거이에요.

"~ㄹ 거예요" 가 맞아요.:) 받침이 있으면 > 이에요 받침이 없으면 > 예요 \^o^/