Answer:
The correct option is: a. reversible reaction
Explanation:
In thermodynamics, Gibb's free energy is the quantitative measure of the spontaneity or feasibility of a chemical reaction, at fixed temperature and pressure.
It can also be described as the maximum available work obtained from a closed system. This maximum work can only be achieved in a reversible process, at fixed pressure and temperature.
The Gibb's free energy (ΔG) is given by: ΔG = ΔH - T.ΔS
