Hydrogen Peroxide Decomposes into Water and Oxygen in a First-Order $\to$

Hydrogen peroxide decomposes into water and oxygen in a first-order process.H₂O₂(aq) $\to$ H₂O( ) + 1/2 O₂(g)
At 20.0 ^$\circ$ C,the half-life for the reaction is 3.92 $\times$ 10⁴ seconds.If the initial concentration of hydrogen peroxide is 0.52 M,what is the concentration after 7.00 days?

A) 1.2 $\times$ 10^-5 M
B) 0.034 M
C) 0.074 M
D) 0.22 M
E) 0.52 M