In the following questions, some of the sentences have errors and some are correct. Find out which part of a sentence has an error. The number of that part is the answer. If there is no error your answer is (4) i.e. No error.
Do you know that it was I (1) / who has done (2) / this piece of beautiful work? (3)/No error.(4)

Answer

B

Explanation

Here, the antecedent of Relative Pronoun .who. is .T. and hence who have done should be used as I agrees with .have..