If your a straight boy and you know it... go get a boy and see what life is about.

That would be kinetic energy

If its history of, then b) because a) implies only present day (now)

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.

Ithink the answer is c. make unnecessarily  wide gestures