<span>On the scale the only external forces are the man's weight acting downwards and the normal force which the scale exerts back to support his weight.
So F = Ma = mg + Fs
The normal force Fs (which is actually the reading on the scale) = Ma + Mg
But a = 0
So Fs = Mg which is just his weight.
Fs = 75 * 9.8 = 735N</span>
The answer is D-Testable
Hope this helps
Explanation :
It is given that,
BMR i.e basal metabolic rate is 88 kcal/hr. So, BMR in watts is converted by the following :
We know that, 1 kilocalorie = 4184 joules
So, 

J/sec is nothing but watts.
So, 
and 
So, it can be seen that the body can accommodate a modes amount of activity in hot weather but strenuous activity would increase the metabolic rate above the body's ability to remove heat.