Sentence Improvement - Verbal and Reasoning

Directions to SolveIn questions given below, a part of the sentence isitalicised and underlined. Below are given alternatives to the italicised part which may improve the sentence. Choose the correct alternative. In case no improvement is needed, option 'D' is the answer.
Q1:

If you are not clear about the meaning of a word, it is wise to look to a dictionary.

A look for

B look at

C look up

D No improvement

ANS:C - look up

No answer description is available.