When exercising in hot weather, you should:

A. drink plenty of fluids before, during, and after exercise
B. workout between 11am and 2 pm
C. exercise as hard as you can
D. wait until you are thirsty before you drink

(A.) drink plenty of fluids before, during, and after exercise.

Explanation:

while exercising, it is important to always drink water (and drinks with plenty of electrolytes, such as Gatorade) and stay hydrated. when you're exercising, especially in hot weather, you'll be sweating. in order to continuously replace the fluid you've lost by sweating, you must drink water. without drinking water during exercise, you may become dehydrated. this may lead to fainting, which may lead to even worse injuries. so, your answer should be (A.)

Hope this helps!