Most muscle relaxants work on the central nervous system. Which of the following is an effect on muscles?

• A. Relax strained, stiff, and weakened muscles
• B. Euphoria
• C. Nausea
• D. Fever

Answer: (A)

Muscle relaxants can calm muscles either by dulling the signals from the nerves to the muscles or, in some cases, by acting directly on the muscle fibers. The key muscle-level effect is relaxation: reducing tension and spasm so that strained or stiff muscles become looser and easier to move.

That described effect—relaxing strained, stiff, and weakened muscles—is what muscle relaxants aim to achieve in the muscles themselves. The other options (euphoria, nausea, fever) are general symptoms or side effects that don’t reflect a direct change in muscle tone or contraction.