IMPORTANT UPDATE:
(1) fixed: conflicting and duplicated header issues
    (a) changed header path in `#include`
    (b) removed conflicinting header files from header (recursive issue)
(2) added: `strcpyToLower` function declaration
(3) added: `getUserSelection` && `exitOnUserRequest` function definition
reverted back: function name from  to .
FIXED: duplicate symbol issue