SHE TURNED THE RADIO AT 7

61. She turned the radio at 7:30. She was still listening to it when her mother came home at 9:00.

A. She has been listening to the radio at 7:30.

B. She had been listening to the radio since 7:30.

C. She has been listening to the radio after 7:30.

D. She has been listening to the radio by 7:30.