C is ans here.

Usage of "Different from" in stead of "different than" is always correct.

Choice D says it is different from the instructurer not what he did.So wrong.

D seems correct

but I choose B because the action should be continuing now also

what is OA?

Hi

The OA is C.

But D also uses..different from and moreover D uses @ that of@, os it is clear that it refer to the way of doing things and not to the instructor

Anyway the reason given for not choosing D is - 'D' maybe a better crafted sentence but it changes the wording'

Myabe it is true as D compares 'way of doing things for both' whereas C and original sentence talks abt - what previous previous instructor did and how new instructor does things differently

Can any expert pls comment?

'C' also uses the correct tense form i.e. "doing things was.....the previous instructor did".

'D' lacks that form.The verb is missing here.

This is called "Parallel comparision" .I read it somewhere in Princeton Review.

I think that 'D' is the answer and not C.
In C, 'what previous instructor did' is compared to 'His way of doing things' which sound absurd and meaningless.
D correctly compares the ways of doing things of the previous instructor with the person referred to by 'his'.