For Questions Assume That an Individual Consumes Two Goods

For questions assume that an individual consumes two goods X and Y. The total utility (assumed measurable) of each good is independent of the rate of consumption of other goods. The prices of X and Y are, respectively, $5 and $10.

$\begin{array}{lcc}\text { Units of the Good } & \text { TotalUtility of } X & \text { Total Utility of } Y \\1 & 50 & 400 \\2 & 95 & 750 \\3 & 135 & 950 \\4 & 170 & 1100 \\5 & 200 & 1220 \\6 & 225 & 1320 \\7 & 245 & 1400 \\8 & 260 & 1450\end{array}$
-If the consumer buys the third unit of Y,

A) the marginal utility of the third unit is 950 units of satisfaction.

B) the marginal utility per dollar spent on Y is 200.
C) the marginal utility per dollar spent on Y is 20.
D) both a and B