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 $\_\_\_\_\_\_\_\_.$

Group of answer choices

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.

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

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.

count must be a static variable in the class, initialized to $0,$ incremented by each add method, and decremented by each remove method