I believe the answer is A. Don't trust me though, lol.
The answer is D (8 to 12)
While doing upper-body exercise routine, fatigue of target muscles can be safely achieved within<span> the short time-frame of about 1.5 minutes (the time-frame for anaerobic pathways) by simply performing 8 to 12 </span>repetitions<span> at a moderate movement speed.</span>
My estimate is that the answer is C, AED cost.
I believe that the answer to this is the last two answers
Answer: Those parts is were all the oxygen is distributed through the human body, and so technically it can be considered the respiratory system.
