Choose the right variant of transforming Direct speech into Reported one:

“Who did you see at the lecture yesterday?” my mother said.

Выберите один ответ:

a. My mother wanted to know who I had seen at the lecture the day before.

b. My mother wanted to know who I had seen at the lecture yesterday.

c. My mother wanted to know who I saw at the lecture the day before.

d. My mother wanted to know who had I seen at the lecture the day before.