To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Base case - This option is incorrect. The base case is an essential part of a recursive function. It provides a condition that allows the function to terminate and prevents infinite recursion.
Option B) Recursive call - This option is correct. The recursive call is the part of the recursive function that calls itself. Without a recursive call, the function would not be able to repeat the process and would not result in infinite recursion.
Option C) Subtraction - This option is incorrect. The specific operation performed in the recursive function (such as subtraction) does not determine whether the function will result in infinite recursion or not.
Option D) Local variable declarations - This option is incorrect. Local variable declarations are not directly related to whether a recursive function will result in infinite recursion or not. They are used to store and manipulate data within the function but do not affect the recursion itself.
The correct answer is Option B) Recursive call. This option is correct because without a recursive call, the function would not be able to repeat the process and would not result in infinite recursion.