Which of the following is the correct expression for the maximum thermal efficiency $$(\eta)$$ of a system undergoing a reversible power cycle while operating between thermal reservoirs at temperatures $$T_{c}$$ and $$T_{h}$$

A

$$ \eta =\frac{T_{c}}{T_{h}}$$

B

$$ \eta =\frac{T_{h}}{T_{c}-1}$$

C

$$ \eta =1-\frac{T_{c}}{T_{h}}$$

D

$$ \eta =1$$