My sister wrote a lot of articles last year. A. A lot of articles were written by my sister last year. B. A lot of articles are written last year by my sister. C. A lot of articles have been

A lot of articles were written by my sister last year.

A lot of articles are written last year by my sister.

A lot of articles have been written by my sister last year.

A lot of articles had been written by my sister last year.