Answer from cs61c-ck (Allen Lee 16583554) for Question 2
b and c are true, a and d are false.

b: If the section of memory to be freed is adjacent to exactly one free block, the chunk to be freed will be coalesced with its adjacent block, merely increasing the size of the adjacent free block, leaving the number of free blocks unchanged.

c: If the section to be freed is exactly between two free blocks, the three sections coalesce, making one big chunk, thereby reducing the number of free blocks by 1.  A call to free cannot reduce the number of free blocks by more than 1 because a section cannot be adjacent to more than two blocks.

d: This is false because c is true.

a: This is false because b and c are true.  The number of free blocks will only increase if the section is not adjacent to any free blocks.