Suppose the Accompanying Table Describes the Demand for a Good

Multiple Choice

Suppose the accompanying table 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 marginal revenue from selling the 4th unit of output is less than $7 because:

A) marginal cost is greater than $3.
B) the consumer only pays $4 for the 4?? unit.
C) it has to charge $1 less for each of the first 3 units of output.
D) demand is perfectly elastic.