A 255-mL gas sample contains argon and nitrogen at a temperature of 65 °C. The total pressure of the sample is 725 mmHg, and the partial pressure of argon is 231 mmHg. What mass of nitrogen is present in the sample?

a) 0.324 g nitrogen 

b) 0.167 g nitrogen

c) 0.0837 g nitrogen 

d) 0.870 g nitrogen