Answer:
A. 53.3% N, 46.7% O
Step-by-step explanation:
1st) It is necessary to add both quantities (10.48g of nitrogen and 11.96g of oxygen) to obtain the total mass of the sample, which represents 100%:
10.48g + 11.96g = 22.44g
22.44g represents the 100% of the sample.
2nd) Now we can calculate the percentage composition of the gas, using a mathematical rule of three and the amount of nitrogen and oxygen:
• Nitrogen:

• Oxygen:

We can also calculate the oxygen percentage by subtracting 100% minus the nitrogen percentage (46.7%):
100% - 4607% = 53.3%
So, the percentage composition is 53.3% N and 46.7% O.