Dear Chanvi, My question to you is why not?
Second, you must go to subject that you like most or have interest in it and for this the very best option I can give you that can help you to discover your need and real choice. Go to Google and read about HRM, Psychology, and scope.
But if you wanna know from other what subject you must go with, can have lots of suggestions here that you must go to HRM which is expected and obvious as this is the place for HR people.
You must go to
https://www.citehr.com/16473-psychology-hr.html and im sure this will certainly help you to know your choice.
You also can go to following discussion where member has already discussed this same topic and have defined how both are connected to each other.
https://www.citehr.com/114784-hr-psychology.html
With my personal and professional opinion, I want you to go with HRM