Help me with this grammar problem

<p>Qn, choose which part in the sentence is incorrect.</p>

<p>After the somber butler strode to the door and asked,"Who is it?" the mysterious vagrant replied, "It is me." </p>

<p>A.After
B.strode
C.Who
D.me
E.No error</p>

<p>The correct answer is D. Why?</p>

<p>It should be 'It is I'.</p>

<p>The book says so too.
But i still don't get it. Why "It is I".
Don't we normally say " It's me"</p>

<p>Spoken english need not necessarily be grammatically perfect english</p>

<p>Don't trust spoken English.
It's simple. The verb "to be" is an intransitive verb and always takes the nominative case of pronouns.
"Me" is the objective form-- it is always the object of the sentence, which is the thing that is being acted upon. If you were to say "He hit me," that would be correct, because 'me' is being hit and is therefore the object.
However, since there is no object in a sentence using the verb 'to be', you should use the nominative form of the pronoun, which is I.</p>

<p>oh, I see.
Thanks a lot!</p>