Charlie's utility function is U(A, B)  AB, where A and B are the numbers of apples and bananas, respectively, that he consumes.If Charlie is consuming 15 apples and 30 bananas, then if we put apples on the horizontal axis and bananas on the vertical axis, the slope of his indifference curve at his current consumption is

A) 16.
B) 2.
C) 4.
D) 1/2.
E) 1/4.

Utility Function

A mathematical representation that defines how much utility or satisfaction a consumer derives from consuming goods and services.

Indifference Curve

A graph representing different combinations of two goods that provide the same level of utility or satisfaction to the consumer.

Apples

A common fruit that comes in many varieties and is used in numerous culinary preparations, also often referenced as a basic economic good in examples.