Consider the Following Reaction That Follows a Second Order Rate

Consider the following reaction that follows a second order rate law .
2 NO₂ (g) →2 NO (g) + O₂ (g)
If [NO₂]_o = 0.0500 M and k = 0.543 M ^{- 1}s ^{- 1}, then what would be the concentration of NO₂ after 1800 seconds?

A) 0.000 M
B) 1.00×10 ^{- 3} M
C) 1.02×10 ^{- 3} M
D) 1.04×10 ^{- 3} M
E) 997.4 M