Final answer:
Type IIb (Fast-twitch glycolytic) skeletal muscle fibers are designed for powerful and quick contractions that produce high force, but they fatigue rapidly due to reliance on anaerobic metabolism.
Step-by-step explanation:
The class of skeletal muscle fibers that produces high, but unsustained, amounts of force is c) Type IIb (Fast-twitch glycolytic). These fibers, also known as 'white' muscle fibers, are adapted for quick and intense movements but fatigue quickly. They primarily use anaerobic glycolysis to produce ATP, allowing for powerful contractions; however, they do not sustain this high-energy output for a long duration due to a quicker depletion of energy reserves.
Type IIb fibers are contrasted with Type I fibers, which are slow-twitch oxidative and can maintain contractions for longer periods as they use aerobic pathways to produce ATP, and Type IIa fibers, which are fast-twitch oxidative-glycolytic and can use both aerobic and anaerobic respiration, thereby providing a mixture of endurance and power capabilities.