How to end a current call and answer a new incoming call?

I was calling a place A. While still calling the place A (and listening to their pre-recorded message), I got an incoming call from a place B. What would I need to do to first end the call with the place A and then to answer the call from the place B? 

(The only options of which I am aware are: 1) to decline the call from the place B, then to end the call with the place A, then to call the place B again… However, place B did not respond then… 2) To accept the call from the place B, and to let the place B listen pre-recorded message from the place A - which would also mean to let the place B know that I am calling the place A, which I did not want to do for privacy reasons.) 

My phone is Samsung Galaxy.