Mark the letter A, B, C, or D to indicate the underlined part that needs correction in each of the following questions.
After the police had tried unsuccessfully to determine to who the car belonged, they towed it to the station.
A. the police
B. unsuccessfully
C. who
D. it to
C
Sau “to” ( giới từ) không dùng “ who” => sửa thành “ whom”
=>Đáp án C.