What is the least sever form of heat illness

Heat exhaustion symptoms can include:

Fatigue
Nausea
Headache
Excessive
thirst
Muscle aches and cramps
Weakness
Confusion or 
anxiety
Drenching sweats, often accompanied by cold, clammy
weakened heartbeat
Dizziness
Fainting
Agitation

Heat exhaustion requires immediate attention. Even though, it is probably the least severe heat — related illness.

Your answer is going to be c. 

explanation:

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.