Dangerous conditions influencing sport injuries include all of the following except:
a. overuse
b. overexertion
c. incorrect technique
d. practicing and drills

Dangerous conditions influencing sport injuries include all answers which you've mentioned (overuse, overexertion, and incorrect technique). It doesn't, however, include practicing and drills - d.

Practicing and drills is the thing which would help us become more profficient at a certain task and eventually sport through it.

D) better spellers i would think