Question

Which sentence uses who correctly?
A.Who is the person that I should call?
B.From who did you receive the call?
C.To who are you speaking?Who did you call?

Answer 1

A.

Answer 2

I believe its A, because B+C would use whom instead of who.

Answer 3

In modern informal English A is correct. Grammatically Whom should I call? is correct because "whom" is the object of "to call" and should be in the objective case.