Skeletal muscle bundles are held together by a common connective tissue layer known as

The correct answer is Fascia.

Let us break down the structure of skeletal muscle connective tissues step-by-step to understand why this option is correct:
1. Skeletal Muscle Organization: A skeletal muscle is not just a single mass of tissue. It is organized into levels of bundles. Individual muscle fibers (cells) are grouped together into bundles called fascicles (or muscle bundles). These fascicles are, in turn, grouped together to form the whole muscle.
2. Connective Tissue Coverings: Different layers of connective tissue support and protect muscle tissue at various levels of organization:
• Endomysium: This is a fine sheath of connective tissue that surrounds each individual muscle fiber.
• Perimysium: This is a layer of connective tissue that groups individual muscle fibers into bundles or fascicles.
• Epimysium: This is an overcoat of dense connective tissue that surrounds the entire skeletal muscle.
• Fascia: This is a common, tough, collagenous connective tissue layer that wraps around and binds together multiple muscle bundles (fascicles) and muscles, holding them in place and connecting them to surrounding structures.
3. Aponeurosis: An aponeurosis is a broad, flat sheet of dense fibrous connective tissue that acts as a tendon to attach muscles to bones or other muscles, rather than a sheath wrapping around bundles.

Therefore, the common connective tissue layer that holds skeletal muscle bundles together is known as fascia.