Given the above definition of the ADTList, the insert and append have different behavior of adding an element in a list. Which method has the constant trend as the notation big-Theta(1) that means the time efficiency does not depend on the size of the elements in the list?

a.

insert

b.

append

c.

both insert and appen

- public interface ADTList {! 7** Remove all contents from the list, so it is once again empty. Client is responsible for reclaiming storage used by the list elements. */5 public void clear(); 1 7** Insert an element at the current location. The client must ensure that the list's capacity is not exceeded. @param item The element to be inserted. */ public void insert(E item); /** Append an element at the end of the list. The client must ensure that the list's capacity is not exceeded. @param item The element to be appended. */9 public void append(E item)