Answer:
C. The array must be sorted
Step-by-step explanation:
Binary search is used to find a values position in a sorted array
From this definition, The Binary search can only be used on an array that has been sorted. It cannot be applied on an array that is not sorted.
Therefore, the additional requirement that is placed on array so that binary search can be used for the location of an entry is found in option c, The array must be sorted.