adding an instance field size of type int to track the number of elements stored in a doubly-linked list optimizes the worst-case runtime complexity (from linear time to constant time algorithm) of which of the following operations defined in listadt? select all which apply. group of answer choices public void add(t object); // adds object at the end of this list public void add(int index, t object); // adds object at position index within this list public t remove(int index); // removes and returns the element stored at position index within this list. public int size(); // returns the number of elements stored in this list. public t get(int index); // returns the element stored at position index within this list