In the linked list implementation of the queue, we had both a destructor and a makeEmpty function because:

A. the destructor needs to call the makeEmpty function
B. the client may want to empty out the queue without destroying it; however, the client shouldn’t have to remember to use makeEmpty to avoid memory leak upon destruction of the queue
C. the makeEmpty function needs to call the destructor; otherwise, the queue cannot be destroyed
D. only one is used to free dynamic memory, the other cannot

B