Write the declaration for class B. The class’s members should be as follows:
• m, an integer. This variable should not be accessible to code outside the class or to any class that extends class B.
• n, an integer. This variable should be accessible only to classes that extend class B or are in the same package as class B.
• setM, getM, setN, and getN. These are the mutator and accessor methods for the member variables m and n. These methods should be accessible to code outside the class.
• calc. This is a public abstract method.
Next, write the declaration for class D, which extends class B. The class’s members should be as follows:
• q, a double. This variable should not be accessible to code outside the class.
• r, a double. This variable should be accessible to any class that extends class D or is in the same package.
• setQ, getQ, setR, and getR. These are the mutator and accessor methods for the member variables q and r. These methods should be accessible to code outside the class.
• calc, a public method that overrides the superclass’s abstract calc method. This method should return the value of q times r.