According to the second law of thermodynamics, __________.

• A. everything in the universe will eventually reach absolute zero
• B. entropy is always decreasing
• C. entropy will increase forever
• D. everything in the universe will eventually be the same temperature

Answer: (C)

Disorder, quantified as entropy, tends to rise in natural processes. The second law says the total entropy of an isolated system cannot decrease; in real (irreversible) processes it increases, and overall the universe’s entropy grows over time toward greater disorder. So saying entropy will increase forever matches this idea: entropy tends to keep increasing as energy becomes more dispersed and systems move toward equilibrium.

The other ideas don’t fit as neatly. Absolute zero is unattainable in practice due to how energy and microscopic states behave, so that statement isn’t supported. Entropy does not generally decrease; it stays the same only for ideal reversible processes and increases in real ones. While systems do move toward a common temperature as they exchange heat, the second law speaks to the direction of energy dispersal and entropy change, not a blanket claim about the entire universe ending at one uniform temperature.