Some of the sentences have errors and some have none. Find out which part of a sentence has an error

Options

A. (1) It is
B. (2) who is to blame
C. (3) for this bad situation
D. (4) No Error

Answer

2

Explanation

am will replace is because -
when the subject of the Verb is a Relative Pronoun (who), the Verb (is) agrees in Number and Person with the Antecedent of the Rel. Pro. A Noun/Pronoun which comes before a Rel. Pro. is called
Antecedent. Here, I is the Antecedent of who (Rel. Pro.) with I so, am is used. Hence, who am to blame is the right usage.