I am going there ____ May,the 12th

I am going there ____ May,the 12th
A.in B.on C.at D.for
This is my new book.Let me show ____
A.you to it B.it to you C.you them D .them to you
what about _____ in the mountain?
A.go hiking B.go to hiking C.going haking D.going to hiking