The Unit Selling Price P (In Dollars) and the Quantity

Multiple Choice

The unit selling price p (in dollars) and the quantity demanded (in pairs) of a certain brand of women's gloves is given by the demand equation . ​
What is the marginal revenue to the nearest cent per day when x = 100?
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A) The marginal revenue when x = 100 is $135.55 per day.
B) The marginal revenue when x = 100 is $141.41 per day.
C) The marginal revenue when x = 100 is $149.82 per day.
D) The marginal revenue when x = 100 is $0.90 per day.