A method int size() in a linked list class returns the number of elements stored in the list by executing the single statement return count; For this to work correctly,

A) count must be a static variable in the class, initialized to 0, incremented by each add method, and decremented by each remove method
B) count must be an instance variable in the class, initialized to 0, incremented by each add method, and decremented by each remove method
C) count must be a local variable in each add and remove method: the add methods must increment count, and the remove methods must decrement count.
D) It is not possible for size to just return the count value: the size method must set count to 0 and then increment count once for each element in the list.

B) count must be an instance variable in the class, initialized to 0, incremented by each add method, and decremented by each remove method