For a reaction, $$N_2O_5(g) \rightarrow 2NO_2(g) + \frac{1}{2}O_2(g)$$ in a constant volume container, no products were present initially.  The final pressure of the system when $$50\%$$ of reaction gets completed is:

A

$$ 5 \text{ times of initial pressure} $$

B

$$ \frac{5}{2} \text{ times of initial pressure} $$

C

$$ \frac{7}{2} \text{ times of initial pressure} $$

D

$$ \frac{7}{4} \text{ times of initial pressure} $$