Boyle's law states that if the temperature of a gas remains​ constant, then PV​=c, where P=pressure​,V=volume ​, and c is a constant. Given a quantity of gas at constant​ temperature, if V is decreasing at a rate of 10in​^3/sec​, at what rate is P increasing when P =60​lb/in^2 and V=20in^3 in​? (do not round your answer.)

a. 30 lb/in^2 per sec
b. 120lb/in^2 per sec
c. 9 lb/in^2 per sec
d. 10/3 lb/in^2 per sec