Final answer:
The question 'What features of nature are simple and universal?' most accurately reflects physicists' endeavor to find fundamental and broadly applicable laws, which exemplifies the essential quest for simplicity and universality in physics.
Step-by-step explanation:
The question which most clearly exemplifies the kind of simple and universal question that physicists seek out is D) What features of nature are simple and universal? This is because this question targets the fundamental core of physics, that is, to unveil the basic laws and patterns that apply broadly across different systems. Physicists seek to understand the underlying order and aim to discover the simplicity within the complexity of phenomena. Thus, inquiry into the simple and universal properties is aligned with the essence of physical investigation and serves as a foundation for further discovery and understanding of the universe.