The assumption in this problem is that the gas, CO2, is ideal and that the ideal gas law is applicable such that,
n = PV/RT
We simply substitute the given values to the equation above,
n = (1 atm)(V) / (0.082 Latm/mol.K)(T)
n = 12.20 V/T
The correct answer is cold fronts
Parasite I think because it is using other plants for nutrients