$$ 1 + 1+1 + 21 = 24$$. 
A cat divides $$24$$ fish into $$4$$ groups, and each group has at least $$1$$ fish. There are at most~\uline{~~~~~~~~~~}~fish in the group that has most of the fish. 

(1) $$6$$ 
(2) $$24$$ 
(3) $$1$$ 
(4) $$21$$ 