A) is the most painful of all athletic injuries.
B) is an injury that can never be healed.
C) can be completely avoided by stretching.
D) is a stretch and/or tear of a ligament.
A sprain is a stretch and/or tear of a ligament. It would cause pain but wouldn't actually dislocate anything. It's not the most painful injury, it can be healed, and stretching would help but not completely avoid a sprain. So that's why D is the answer.
