Final answer:
The principle stating that the simplest explanation is usually preferred is known as Occam's Razor, which is a heuristic guideline rather than a scientific law or principle.
Step-by-step explanation:
The principle that suggests the simplest explanation of a phenomenon is usually preferred over more complex explanations is known as Occam's Razor. This principle is not a scientific law or a physical principle like Newton's laws of motion or Boyle's law, but rather a heuristic guideline that recommends selecting the explanation that makes the fewest assumptions when confronted with multiple competing hypotheses.
Scientific laws, such as the law of conservation of energy, describe the fundamental rules of nature that apply universally. On the other hand, principles like Pascal's principle specifically explain certain phenomena under particular conditions and are not as broadly applicable as laws. The mention of Pascal's principle here illustrates the distinction between a principle and a law in scientific terminology, though the two terms are sometimes used interchangeably.
To answer the question, the principle that the simplest explanation is preferred is a statement of A) Occam's Razor.