Question

Swimming alone

A. increases the benefits of swimming for cardiorespiratory endurance.
B. is acceptable in a pool but never in a lake or an ocean.
C. is OK as long as you've been swimming for at least five years.
D. is never safe, regardless of ability.

Answer 1

is never safe, regardless of ability.
Better safe than sorry; what if you're in an accident?

Answer 2

d... because you could drown and there would be no one to help u