Using the Information Below,calculate the Average Total Depreciable Life of the Assets

Using the information below,calculate the average total depreciable life of the assets:
$$\begin{array}{l}\text { Infarmation from the Balance Sheet: }\\\begin{array} { l c c } & \mathbf { 2 0 1 2 } & \mathbf { 2 0 1 1 } \\\text { Depreciable As5ets } & \mathbf { 3 0 0 , 0 0 0 } & 400,000 \\\text { Accumulated Depreciation } &\underline{ ( 175,000 ) } &\underline{ ( 100,000 ) }\\\text { Depreciable Assets (Net) } & \$ 425,000 & \$300,000\end{array}\end{array}$$
$\begin{array}{lccc} \text { From the Incame Statement } & 2012 \\ \text { Depreciation Expense} & \$ 50,000\end{array}$

A) 6.54 years
B) 7.25 years
C) 6.91 years
D) 9.15 years.