Under which conditions does CH4 have the same number of molecules as 100cm^3 of O2 at 27 degrees celsius and 1.0x10^5 Pa?

Options:A: 50cm^3, 54 degrees celsius, 1.0x10^5 Pa B: 50cm^3, 327 degrees celsius, 1.0x10^5 PaC: 100cm^3, 54 degrees celsius, 2.0x10^5 PaD: 100cm^3, 327 degrees celsius, 2.0x10^5 Pa
The equation to use in this question is PV = nRT where P=Pressure in Pa, V=Volume in dm^3, n=number of mols (this is what we're trying to find out), R (gas constant found in data booklet) = 8.314, T=Temperature in Kelvin.
NOTE: All volume values we are given are in cm^3, so these must be converted to dm^3. To do this, simply divide the value by 1000.
Firstly we must find out the number of mols of O2 that we have. We do this by putting in the data we are given in the question into the previously mentioned equation:Original: 1.0x10^5 x 0.1 = n x 8.314 x 300.Rearranged: n = (1.0x10^5 x 0.1)/(8.314 x 300) = 4.00930158 = 4mols.
Then we must calculate the other options to see which n value matches this value. From now on I will not show the original equation but instead just the rearranged one:A: n = (1.0x10^5 x 0.05)/(8.314 x 327) = 1.839129165 = 1.84mols.Therefore this answer is not correct.
B: n = (1.0x10^5 x 0.05)/(8.314 x 600) = 1.002325395 = 1mol.Therefore this answer is not correct.
C: n = (2.0x10^5 x 0.1)/(8.314 x 327) = 7.35651666 = 7.36mols.Therefore this answer is not correct.
D: n = (2.0x10^5 x 0.1)/(8.314 x 600) = 4.00930158 = 4mols.This is the correct answer as it matched the original O2 answer of 4mols.