Question

Good evening,

Answer 1

Hello!
Here i would say: Good teachers are listening to the pupils. 

Answer 2

Hi there, in this case, i would say that C is correct, why?
Because if you say are listening, it means kind of different, then they are listening Always, or something like that. A, and B, are improper way of talking, and so as D. And that only one is C.
Hope that this would help you! =)