Statements: Some A are B. Some C are A.
Conclusions:
(I) Some C are B.
(II) Some B are A.

We consider A , B and C as 3 sets, and then construct a venn diagram. 
Some A are B: This implies there is some intersection between A and B. 
Some C are A. This implies there is some intersection between C and A.

So the venn diagram can be constructed as :

Thus, we can see there is no overlap between B and C based on the information given to us. So we cannot conclude that some C are B.

However, there is an overlap between A and B , which means that we can conclude some B are A .

Hence, only conclusion II follows, which means option B is the correct answer.