Kicked out of school in kindergarden

Things are rough at B school. He has so much anger. I know a lot is leftover from the preschool. 

I dread pick up now. To find out what he did. Yesterday he hit 4 kids. He punched a kid that was playing with his best bud K. Then at carpet time a girl was sitting close and so he punched her hand and ground her fingers in to the carpet. There was 2 more but I have no clue what to do. 

I'm thinking of homeschooling. But B and I are so alike personality wise I'm not sure if that would work. 

I also wonder if B is not being challenged enough. He is smart as a whip when it comes to learning. He loves science. 

I just don't know what to do. I'm in tears.