Choose the letter A, B, C, or D to indicate the underlined part that needs correction

Choose the letter A, B, C, or D to indicate the underlined part that needs correction.
1. You mustn't to park here. This is a restricted are
   A. mustn't       B. to park     C. here      D. restricted 
2. It was at her house that we often gather for our study
   A. was             B. that          C. for         D. study
Sửa lại từ đúng giúp mình luôn nha