Suppose the Table Below Describes the Demand for a Good

Suppose the table below describes the demand for a good produced by monopolist. $$\begin{array} { | c | c | } \hline \text { Price } & \text { Quantity } \\\hline \$ 10 & 1 \\\hline \$ 9 & 2 \\\hline \$ 8 & 3 \\\hline \$ 7 & 4 \\\hline \$ 6 & 5 \\\hline \$ 5 & 6 \\\hline \$ 4 & 7 \\\hline\end{array}$$ The monopolist's total revenue from selling 3 units is ______, and the monopolist's marginal revenue from selling the 3^rd unit is ______.

A) $28; 8
B) $24; 6
C) $52; 1
D) $24; 8