Question

🐶🐾

どちらも答えが1になるのですが、なぜそうなるのか分からないので教えて頂きたいです。
他の選択肢が間違っている理由まで教えて下さると助かります。

25 of 500 students attended the special lecture last Wednesday. Chod
An audience
2 Audience
4) Much audience
Audiences
38

Central Park is a wonderful place for a concert
Manhattan.
(1) in that
2 in which
③3③ which
33 it is located in the middle of
4 where