Answer from cs61c-ae (Zhibo Chen 15283355) for Question 2
Statements B and C are true.  Statement A is not always true because the freed block may combine with a neighboring block and not increase the number of blocks.  B is true because the freed block can combine with one other free block and not increase the total count.  C is true because the freed block can at most combine with the two free blocks on both sides and decrease the total count of free blocks.  Statement D is not possible because one would have to combine the freed block with three other blocks.