Quiz · Building and the Preprocessor · lesson 3 of 7Quiz — why #pragma onceWhat does #pragma once at the top of a header file do?[A]Skips the header if it was already included into the same .cpp file[B]Compiles the header once for the whole project and reuses it[C]Makes the functions declared in the header visible to other .cpp files[D]Allows functions defined in the header to appear in several .cpp files← Back#include, #define and include guardsNext →Quiz — SQUARE(x + 1)