Answer from cs61c-aw (wing hin kao 16500429) for Question 2
a is false because if the block being freed is adjacent to either neighbor, the adjacent blocks are combined.

b is true, the same reason in a.

c is false because suppose that a block of size 16 becomes free and that it starts at index position 48 in the storage array. This block may be merged with a block of size 16 that starts in position 32. It may not be merged with a block of size 16 that starts in position 64, because the resulting block would be of size 32.

d is true, the same reason in c.