What file contains the controller class for the frontend path /mymodule/custom?

Your module, MyCompany_MyModule, is using the frontName mymodule. You need to locate the class responsible for the frontend path /mymodule/custom.

What file contains the controller class for the frontend path /mymodule/custom?
A . Controller/Custom/Index.php
B . Controller/Custom.php
C . Controller/MyModule/Custom/Index.php
D . Controller/Frontend/MyModule/Custom.php

Answer: A

Explanation:

Reference: https://www.simicart.com/blog/magento-create-controller/