The Figure Below Shows a Consumer Maximizing Utility at Two

Multiple Choice

The figure below shows a consumer maximizing utility at two different prices (the left panel) and the consumer's demand for good X at the same two prices of good X (the right panel) .The price of good Y is $4.50.When the price of X increases from point S to point R along the demand curve,the substitution effect of the price increase is ________.

A) -6
B) -7.5
C) -8
D) -9
E) -10