$[2$ points$]$ Consider Java's dynamic data structure java.util.ArrayList. It automatically doubles its size when it's full and halves its size when less than one$-$quarter of the cells are filled with data. For each of the following operations, identify its running time by the following listed orderof$-$growth term. Assume $n$ is the original input data size.

A: $0(1)$

B: $O(logn)$

C: $O(n)$

D: $O(nlogn)$

E: $O(n^2),$ F: $O(n^3)$

$5\mathrm{.}1)$ Return the element at index $\frac{n}{2}$ in the list.

$5\mathrm{.}2)$ Worst$-$case running time to perform $n$ consecutive add$-$to$-$back operations. Each add$-$to$-$back operation adds an element to the back of the list.

$5\mathrm{.}3)$ Worst$-$case running time to perform $n$ consecutive remove$-$from$-$front operations. Each remove$-$from$-$front operation removes the element at the front of the list, also shifting all remaining elements one position to its left.

$5\mathrm{.}4)$ Maximum number of times the array is resized when performing $n$ consecutive removefrom$-$back operations.