Final answer:
Entropy tends to increase, which aligns with the second law of thermodynamics indicating that systems naturally progress towards greater disorder and less available energy for work. So the correct option is D.
Step-by-step explanation:
The statement that agrees with the second law of thermodynamics is D. Entropy tends to increase. This law, which is a fundamental principle in physics, states that the total entropy of a system either increases or stays the same in a spontaneous process; it never decreases. Entropy can be thought of as a measure of disorder, and the second law suggests that natural processes tend to lead toward more disordered states. Heat energy spontaneously transfers from a high-temperature body to a low-temperature body and in the process, the entropy of the system increases, as energy becomes more dispersed and less available for doing work.