A legislative committee is weighing the pros and cons of a clean-air program. If it spends $1 million on the program, the air will be cleaner by 20 percent. If it spends $2 million, the air will be cleaner by 30 percent. If it spends $3 million, the air will be cleaner by 35 percent. After comparing opportunity costs and benefits at the margin, the committee agrees to fund the program with $2 million. Why did it not choose to appropriate $3 million?



a.

At $3 million, the air is not improved as much as the committee would like.


b.

At $3 million, the costs are no longer worth the benefits.


c.

It was too much to spend without a guarantee.


d.

The air is improved by the same amount whether $2 million or $3 million is spent