Question $6$

Linked Lists lend themselves easily to recursive solutions, and it is common to traverse a list by processing a single element and then recursively calling the function on the remaining sub$-$list. It does this by accepting a pointer to the current position in the list as a parameter. In the answers below, this has been referred to as the list pointer.

What criteria is often used as the base case that ends the recursion, and allows the function to return to the original call?

The data element of the node pointed to by the list pointer is storing $-1.$

The list pointer points to the beginning of the list.

The list pointer is NULL.

None of the above.