Final answer:
Red muscle fibers possess a slow oxidative rate and are resistant to fatigue. They are dense with capillaries, rich in mitochondria, and contain myoglobin, making them ideal for endurance activities. The correct option is A-Slow (oxidative) rate and fatigue resistance.
Step-by-step explanation:
Red muscle fibers tend to have a slow (oxidative) rate and fatigue resistance. This can be attributed to their high density of capillaries, rich presence of mitochondria, and substantial amounts of myoglobin, which stores oxygen for muscle activity.
These features enable red muscle fibers, also known as slow-twitch or Type-I fibers, to effectively carry oxygen and sustain prolonged aerobic (oxygen-using) activity. They are capable of contracting for long periods without producing a great deal of force, which is why they are essential in endurance-based activities such as long-distance running or cycling.
Fast-twitch fibers, including Type-IIa and Type-IIx, are less abundant in mitochondria and myoglobin. They contract rapidly and powerfully but fatigue more quickly than their slow-twitch counterparts. Fast-twitch fibers are associated with short, strenuous activities like sprinting or weight lifting due to their ability to produce quick, powerful movements and their reliance on anaerobic metabolism, leading to faster fatigue.