Final answer:
The correct answer is D) EB/EA = EC/EB indicates energy conservation, which reflects the principle that in the absence of non-conservative forces, mechanical energy remains constant in a closed system.
Step-by-step explanation:
The concept of mechanical energy conservation states that the total mechanical energy of a system (the sum of kinetic and potential energy) remains constant in the absence of non-conservative forces like friction. According to this principle, the ratio EB/EA should equal 1 if mechanical energy is conserved between points A and B, because mechanical energy at B (EB) should be the same as mechanical energy at A (EA). Similarly, EC/EB should also equal 1, indicating that the mechanical energy at C (EC) is equal to that at B (EB), again assuming no energy loss or gain.
Where non-conservative forces are present or energy is added or removed from the system, these ratios may differ from 1. However, in an ideal closed system with no friction or external energy input or output, both ratios should indeed be 1, reflecting the conservation of mechanical energy. Thus, the correct answer to the student's question would be D) EB/EA = EC/EB indicates energy conservation.