Two soap bubbles coalesce to form a single bubble . If V is the subsequent change in volume of contained air and S the change in total surface area , T is the surface tension and P atmospheric pressure ,which of the following relation is correct ?

Question

$(a)\;4 \normalsize PV+3 \normalsize ST=0\qquad(b)\;3PV+4ST=0\qquad(c)\;2PV+3ST=0\qquad(d)\;3PV+2ST=0$