find errors

1) i'm not satisfied with (a) your explanation of where (b)  you was last night (c). no error (d)

2) i came into  (a) the room when  (b) mary played the piano. (c) . no error (d)

3) the man (a) was driving (B) herds of cattle. (C) . no error (d)

4) there is (A) some sheep (b) in the field (c) no error (d)

5) playing (a) the drums and (b) singing are difficult.(C) no error (d)