Heat engine is a device which is used to convert the heat energy into useful work
Heat engine extracts heat from high temperature reservoir and then convert that extracted heat into useful work
this process efficiency is calculated by the formula
[tex]\eta = 1 - \frac{T_2}{T_1}[/tex]
here we know that
[tex]T_1[/tex] = temperature of high temperature reservoir
[tex]T_2[/tex] = temperature of low temperature reservoir
so now from this we can say that high efficiency heat engine will convert more work
so here correct answer will be
HEAT
