B.
his or her
is the answer
They are describing colonel pickering from pygmalion, a play by george bernard shaw.
The 3rd one is the answer
4) Time-consuming lab work
3) Exhaustive note taking
It's asking you proof that Ramirez is a demanding teacher not about the course itself so it is not 1, 2, 4 or 6. It is 4 and 3 because it shows Ramirez was demanding by enforcing a heavy load of work
