An oxygen cylinder has a volume of 50.0 liters and a pressure of 200.0 atmospheres. If this cylinder is used to supply oxygen to a patient at a flow rate of two liters/minute ( at 1.00 atm pressure) how long will the take last?
a. 50.5 hours
b. 83.2 hours
c. 135 hours
d. 1.35 x 10^4 hours