Code Example 17-1 class PayCalculator { private: int wages; public: PayCalculator& calculate_wages(double hours, double wages) { this->wages = hours * wages; return *this; } double get_wages() { return wages; } }; (Refer to Code Example 17-1.) What coding technique is illustrated by the following code? PayCalculator calc; double pay = calc. calculate_wages(40, 20.5).get_wages(); a. self-referencing b. function chaining c. dereferencing d. class chaining