Do you mean to say

Do you mean to say she __now?

a.comes

b.doesn't come

c.has not come

d.isn't coming

http://www.britishcouncil.org/learnenglish-central-test-test-your-level.htm

http://www.learnenglish.org.uk/test/grammartest.html

Hello,

Which is the most precise answer?

Please explain their grammar points,especially the differences between a and d.

Thanks.

Mister Micawber,

I would like to thank you for the explanation.However, I have found one example of the present perfect tense which used the word "now"  in the

British council grammar test(http://www.britishcouncil.org/learnenglish-central-grammar-present-perfect-past-simple.htm).

The example under the third paragraph of the Present perfect vs.past simple is:

" I haven't got my books now."

Could you tell me why this sentence can be used?

Is the sentence "Do you mean to say she has not come now? " informal or something else?

Thank you.

With best wishes.