Final answer:
The formation of a hematoma versus a simple contusion is primarily due to damage to larger caliber blood vessels, which allows a greater accumulation of blood in the tissue.
Step-by-step explanation:
The key factor that results in the formation of a hematoma versus a simple contusion after a soft tissue injury is C - Damage to larger caliber blood vessels. A hematoma occurs when a large amount of blood collects outside of the blood vessels, which is more likely when larger vessels are damaged. In comparison, a contusion, commonly referred to as a bruise, usually results from damage to smaller blood vessels like capillaries. This damage causes blood to leak into the surrounding tissues, but does not usually result in a significant accumulation of blood as seen with a hematoma.