adds one element to the array that ptr is pointing to always causes a run time error adds 1 to whatever ptr is pointing to advance ptr by one unit of the type of variable to which ptr points Question 24 Given that p1 is a pointer, p1++ adds one element to the array that p1 is pointing to advances p1 by one unit of the type of variable to which p1 points adds 1 to whatever p1 is pointing to always causes a run time error