What will happen if the recursion does not reduce the problem in some manner and reach the base case?

When recursion is implemented in a program, it relies on reducing the problem size and approaching a base case at each step. If the recursive function fails to reduce the problem or does not define a base case, the function will continue to call itself indefinitely without ever reaching a point at which it can resolve the recursion and return a final value.

This results in what is known as infinite recursion. Each new recursive call consumes more resources, typically in the form of stack memory, which can eventually lead to a stack overflow error or cause the program to crash. Infinite recursion is a common pitfall in programming when conditions for breaking out of recursion are not correctly implemented. Thus, the correct answer highlights that continuous recursive calls without convergence on a base case culminate in this endless loop of function calls.