The answer that sounds most correct would be: B) Open back and sufficient tread.
Answer:
Target heart rate is generally expressed as a percentage (usually between 50 percent and 85 percent) of your maximum safe heart rate. The maximum rate is based on your age, as subtracted from 220. At an 85 percent level of exertion, your target would be 145 beats per minute.
It would be A, with out water we would dry up and die, being that our body is 70 some percent of water
