Write the declaration for class B . The class’s members shou…

Write the declаrаtiоn fоr clаss B . The class’s members shоuld be:• m , an integer. This variable should not be accessible to code outside the class or to   member functions in any class derived from class B .• n , an integer. This variable should not be accessible to code outside the class, but   should be accessible to member functions in any class derived from class B .• setM , getM , setN , and getN . These are the set and get functions for the member   variables m and n . These functions should be accessible to code outside the class.• calc , a public virtual member function that returns the value of m times n .