$51.$

A project requires $600$ If of fencing for a storage area. The purchase price of fencing is $$4\mathrm{.}40/1$ The initial salvage value of a new fence starts at $$1\mathrm{.}00/$lf and is reduced at the rate of $25\%$ per yer A fence can be rented for $$1\mathrm{.}50/$If per year but has no salvage value. The interest rate is $4\%.$ The project duration $($years$)$ at which it first becomes cheaper to purchase rather than to rent is most nearly:

$.2\mathrm{.}5$

O B$.2\mathrm{.}8$

O C$.3\mathrm{.}2$

O D$.3\mathrm{.}5$