Why is Binary Search a divide and conquer algorithm?

Question

I was asked if a Binary Search is a divide and conquer algorithm at an exam. My answer was yes, because you divided the problem into smaller subproblems, until you reached y

Answer 1

The Merge Sort and Quick Sort algorithms use the divide and conquer technique (because there are 2 sub-problems) and Binary Search comes under decrease and conquer (because there is 1 sub-problem).

Therefore, Binary Search actually uses the decrease and conquer technique and not the divide and conquer technique.

Source: https://www.geeksforgeeks.org/decrease-and-conquer/