A small company heats its building using a gas furnace. It expects to spend $$$$9020$ on natural gas the first year. The cost of the natural gas is expected to incrase by $10\%$ per year every subsequent year. There is also the maintence coston the gas furance which is expected to be $851$ in the first year every subsequenct year. The planning horizon is $15$ years and the company uses an annual interest rate of $20\%$ for econmic analysis of its investments.

A$.$The project annual cost of natural gas in year $15$ is$.$

B$.$ The projected annual maintenace cost of the furance in year $15$ is$.$

C$.$The total present worth of operating and maintaining the furnace over the $15$ years is