In an absorption refrigeration system, the heat energy \(Q_{1}\) is supplied at temperature \(T_{1}\) while the system absorbs heat energy \(Q_{3}\) from a cold space at temperature \(T_{3}\). If the ambient temperature is \(T_{2}\), then the COP of the refrigerator (ignoring the negligible amount of heat supplied to the pump) is

(a) \(\frac{T_{3}\left(T_{2}-T_{1}\right)}{T_{1}\left(T_{1}-T_{2}\right)}\)

(b) \(\frac{T_{1}\left(T_{2}-T_{3}\right)}{T_{3}\left(T_{1}-T_{2}\right)}\)

(c) \(\frac{T_{3}\left(T_{1}-T_{2}\right)}{T_{1}\left(T_{2}-T_{3}\right)}\)

(d) \(\frac{\left(T_{1}-T_{2}\right)}{\left(T_{2}-T_{3}\right)}\).