In the following question, out of the four alternatives, select the alternative which will improve the bracketed part of the sentence. In case no improvement is needed, select "no improvement".
He began to ask about his enemies who (had been hunting) him. (a) is been hunting (b) was been hunting (c) had been hunted (d) no improvement

Options

A. is been hunting
B. was been hunting
C. had been hunted
D. no improvement