Answer;
[tex]B;\text{ \$22,500}[/tex]Explanation;
From the question, we have it that for every $9 spent, $16 is made
So we have a ratio of 9 to 16; expenditure to income
This must stay constant
We will use this to make an evaluation as follows;
Let us call the amount spent as x
Thus;
[tex]\begin{gathered} \frac{9}{16}=\frac{x}{40,000} \\ \\ x\text{ = }\frac{40,000\times9}{16} \\ \\ x\text{ = \$22,500} \end{gathered}[/tex]