What are methods used to stimulate muscles?

The correct choice focuses on methods that directly engage the muscles and promote their activity or function. Massage increases blood circulation to the muscles, providing them with oxygen and nutrients while also helping to relax tension. Nerve impulses are essential for muscle contraction, as they trigger the signals that cause muscles to contract and move. Light rays, depending on their type (such as infrared), can also stimulate circulation and enhance muscle function through light therapy techniques.

The other choices contain elements that may support muscle health or overall well-being but do not specifically focus on direct methods to stimulate muscle activity. For example, drugs can aid in pain relief or muscle relaxation but do not actively stimulate muscle function. Heat and cold can influence muscle activity and recovery but are more about modulation rather than direct stimulation. Similarly, while exercises can stimulate muscles, stretching typically promotes flexibility rather than direct stimulation. Hydration benefits are critical for muscle function but do not directly cause muscle stimulation. Lastly, breathing, walking, and sitting are activities related to movement and overall health rather than targeted muscle stimulation techniques.