Which type of psychology is the most prominent and widely practiced professional specialty in the field of applied psychology

A)  school 
B)  developmental 
C)  cognitive 
D)  clinical

Clinical

Pertaining to the assessment and treatment of patients in medicine and psychology; often used within contexts involving medical and therapeutic settings.

Applied Psychology

The branch of psychology concerned with applying psychological principles and research to solve practical problems in various fields such as business, education, and health.

Professional Specialty

This term refers to a specialized area within a profession in which an individual focuses their expertise and skills, often requiring additional training and certification.