[My sentence]
What/Which/Who do you think is more important to a company, a leader who can inspire employees or a leader who can solve complex problems?
---
I have a feeling that all three options work in this context, but I'm not sure about the "what" one. What do you think?
[I just discussed it with a friend.]
Friend: All three work.
Me: Could you tell me about "what"? Can it be used to ask about "people" ?
Friend: Sure sometimes, like in your example. Sometimes 'who' is more appropriate. Some somewhat random examples:
"What technician did this?" - asking about a type of person.
"Who technician did this?" - is wrong.
"Who did this?" - asking about a person.
"What did this?" - asking in general. The answer could be a person, could not be.
Me: And this is a question of choosing
from a limited number. Can we use "what" [rather than "which"] in this context?
Friend: Using 'which' makes it more clear that the question is exclusively about the options being presented. In your example, the options are presented in the question, so it's equally appropriate to use which', and 'what' also works.
"What color do you like?" - open ended question, I can answer however I like.
"Which color do you like?" - I'm expecting to have options to choose from. If they've not already been mentioned, I'll respond with "From which options?"
"It comes in green or red, what/which color do you like?" - same thing to me.
---
I agree with the friend, but I'd also like to hear your opinion.