A Scientist Conducts an Experiment to Determine the Rate of the Following

A scientist conducts an experiment to determine the rate of the following reaction:
N₂(g) + O₂(g) $\rightarrow$ 2NO(g)
If the initial concentration of N₂ was 0.500 M and the concentration of N₂ was 0.450 M after
0) 100 s, what is the average rate of the reaction?

A) 0.500 M/s
B) 1.00 M/s
C) 5.00 M/s
D) 10.0 M/s
E) 0.250 M/s