Answer:
I would say Option B
Explanation:
A controlled experiment is where you have two or more independent variables, that way you have an experiment to compare results with.
Current Procedural Terminology
Current Procedural Terminology (CPT) is a medical code set that is used to report medical, surgical, and diagnostic procedures and services to entities such as physicians, health insurance companies and accreditation organizations. Might not exactly be an answer, but I hope it helps
