How to solve this...

When the valve between the 2.00 L bulb in which the gas pressure is 2.00 atm, and the 3.00 L bulb, in which the gas pressure is 4.50 atm, is opened, what will be the final pressure in the two bulbs? Assume the temperature remains constant.

a. 6.50 atm

b. 3.00 atm

c. 3.50 atm

d. 3.67 atm

e. 2.83 atm