Solid Ammonium carbamate dissociates as:

NH₂COONH₄(s) ⇔ 2NH₃(g) + CO₂(g)

In a closed vessel, solid ammonium carbonate is in equilibrium with its dissociation products. At equilibrium, ammonia is added such that the partial pressure of NH₃ at new equilibrium now equals the original total pressure. Calculate the ratio of total pressure at new equilibrium to that of original total pressure. Also find the partial pressure of ammonia gas added.

A. 27/31
B. 31/27
C. 4/9
D. 41/9