The statement that most clearly provides evidence that a scientific law is a description while a scientific theory is an explanation is:
"Laws of motion state that for any action force, there is an equal and opposite reaction force, while theories state that contact forces are due to electrostatic forces between the charged particles that make up matter."
This distinction illustrates that laws describe observable phenomena (such as the relationship between action and reaction forces), while theories provide explanations for how and why those phenomena occur (such as the explanation involving electrostatic forces).