subject verb agreement - Which is the correct question ("Who has" vs "Who have")?

The situation is that:

We've already read three English novels.

Which is the correct question for that situation?

1. 
   

   Who has already read three English novels?

   
   


2. 
   

   Who have already read three English novels?

   
   

Or could both be correct?

Please also provide the grammatical reasons for your answers.