Which of the following best describes the Cardinal Principle of McFall's Manifesto?

• A. Clinical Psychology is only a legitimate field if it is founded in science.
• B. Only clinical psychologists who are trained in medical schools should be qualified to practice clinical psychology.
• C. Clinical Psychology should be divided into 2 subfields - Scientific Clinical Psychology and Applied Clinical Psychology.
• D. Clinical Psychology needs to more seamlessly integrate Ph.D. programs and Psy.D. programs.