In the following ten questions, a sentence/a part of the sentence is underlined. Below are given alternatives to the underlined part which may improve the sentence. Choose the correct alternative. In case no improvement is needed blacken the circle corresponding to "No improvement".
Mr.Mukherjee knows ten languages, `underline("isn.t it")`?

Options

A. doesn't Mukherjee
B. No improvement
C. hasn't he
D. doesn't he

Answer

D