(Requires Calculus) in the Equation $\widehat { \text { TestScore } } = 607.3 + 3.85 \text { Income } - 0.0423 \text { Income } { } ^ { 2 }$

Multiple Choice

(Requires Calculus) In the equation $\widehat { \text { TestScore } } = 607.3 + 3.85 \text { Income } - 0.0423 \text { Income } { } ^ { 2 }$
the following income level results in the maximum test score

A) 607.3 .
B) 91.02 .
C) 45.50 .
D) cannot be determined without a plot of the data.