Sentence Correction - Verbal and Reasoning

Directions to SolveWhich of phrases given below each sentence should replace the phrase printed inboldtype to make the grammatically correct? If the sentence is correct as it is, mark 'E' as the answer.
Q1:

The easiest of the thing to do is to ask the address to the postman.

A of the things to do

B among the things did

C of the thing to be done

D of all the things done

E No correction required

ANS:A - of the things to do

No answer description is available.