American Board of Opticianry (ABO) Practice Test 2026 - Free ABO Practice Questions and Study Guide

The correct answer is Electromagnetic Theory, not Apex, Corpuscular, or Photons. A, Corpuscular, is incorrect because it focuses on light as being made up of particles rather than waves. C, Photons, is incorrect because it is not a theory itself, but rather a concept within the electromagnetic theory. D, Apex, is incorrect because it is not a scientific theory that explains light as moving in a series of wave pulsations. It is important to understand the context and definitions of each answer choice in order to determine the correct answer.