I chose other because I think that increasing strength relative to bodyweight is vital in sprinting as it is the key component in increasing stride length which is the number one factor in increasing speed (biomechanically speaking).
Let's analyze the others:
"Learning" to recruit motor units: Can easily be done on the track and should be. Weights aren't necessary there.
Developing specific strength: This might be a choice based on how you view specific strength, but I think plyos may be a bit more necessary than weightlifting in some aspects.
Developing general strength: You can do this via bounds, hills, plyos, bleachers, Ext. Tempo to some extent (strengthening of bones, tendons, joints, etc.). You don't need weights for this.
Raising work capacity: You can do this through bodyweight circuits, but can also be helped by weights. However, this is more or less done through circuit training and not heavy lifting. But, again I feel this can be a possible choice.
Hypertrophy: Sprinters don't need this…period.
Injury Prevention: Proper training, stretching, warming up/cooling down, post-workout recovery methods and things of that nature are best suited to prevent injuries. Not weights. They actually can cause injury if done improperly.
This is just my 2cents that is probably going to get ripped. So, let's here other's responses.
