... are those girls? They are students. Which choice do you think is correct?

John: ___ are those girls? Tom: They are students.
(A) Who (B) What
Which choice do you think is correct?

I’d use “who”. Calling a person “what” sounds demeaning.

Hello,

I’d use ‘who’ too, coz what dosen’t make sense in that question.

Hello,

I’d use ‘who’ too, coz what dosen’t make sense in that question.

What about the following conversation?

A: What is your father? (What does your father do for a living?)
B: He’s a doctor.

Now if I ask “What are those girls?”, doesn’t it mean, “What’s the profession of those girls?” ?

Hi Daemon

I’d put it this way:

I would not dive right into a question about someone’s profession by asking “What is (someone)?” if there had not already been some previous discussion about professions.

The question “What is (someone)?” does not inherently mean “What is (someone’s) profession?” But it could be used to mean that in the right context.
.

But who is going to take the advice of someone who can’t spell?

I don’t think so. As Jamie pointed out, “what” sounds demeaning, but not wrong. In my book it’s similar to identifying a person with a lifeless thing.