Sql Query using group clause

Question

this is my table snapshot of sql server.

my table 

i want to write a sql query , which will return only 3 row, whcih contain max offer from 3 diffrent category. like in my result there should be 3 different category id, and correspondence to that category's Offer that offer should be maximum in that category

this is my desired output

My Output 

 

you can see there is 3 diffrent category , and offer belongs to that category is maximum from that category