Which searching method requires that the list be sorted?

Binary Search

Explanation:

Binary search is a search which we can apply on sorted list. This search compares the search element with the middle  element of the list. If it is greater than the middle element then again we apply search on right list

if it is less that the list then it will apply search on left list. This process happens recursively until you find the search element.

In Worst and average Case Performance :0(nlogn)