A Clinic Uses Doctors and Nurses to Serve the Maximum

A clinic uses doctors and nurses to serve the maximum number of patients given a limited annual payroll. The clinic currently has 10 doctors and 30 nurses. The last doctor hired can serve 300 additional patients, while the last nurse hired can serve 200 additional patients. If doctors make $60,000 a year and nurses make $20,000 a year, the clinic

A) is making the correct hiring decision because doctors are more productive than nurses.
B) is making the correct hiring decision because doctors are paid more than nurses.
C) could serve more patients with the same payroll by hiring more doctors and fewer nurses.
D) could serve more patients with the same payroll by hiring more nurses and fewer doctors.