Suppose That a Sawmill Processes Logs into Four Grades of Lumber

Suppose that a sawmill processes logs into four grades of lumber totaling 500,000 board feet as follows at a joint cost of $300,000: $\begin{array}{lrr}\text { Grade }& \text { Board Feet } & \text { Final Sales Value }\\\text { First and second } & 75,000 & \$ 56,250 \\\text { No. } 1 \text { common } & 200,000 & 180,000 \\\text { No. } 2 \text { common } & 100,000 & 105,000 \\\text { No. } 3 \text { common } & 125,000 & 127,500\end{array}$ What amount of joint costs will be allocated to first and second using the physical units method?

A) $300,000
B) $45,000
C) $36,000
D) $225,000