Again, consider the following recurrence relation named M for mysterious: M(x, y) = M(x-y, y) if x > y //x and y are non-negative integers M(x, y) = M(x, y-x) if y > x M(x, y) = x if x = y What does this code do? (Characterized from a mathematical standpoint) It always returns 1

It calculates the least common divisor

It calculates the average

It calculates the greatest common divisor.

It calculates the least common multiple

It calculates the greatest common multiple