In the question given below, a part of the sentence is in bold and italicised. Below are given alternatives to the bold and italicised part which may improve the sentence. Choose the correct alternative. In case no improvement is needed, choose option 'D' as the answer.

Whenever my students come across new words, I ask them to look for them in the dictionary.

A.

to look it up

B.

to look them up

C.

to look at them

D.

No improvement

Correct answer is B

No explanation has been provided for this answer.