how to calculate ?

To increase safety at a bad intersection, you must decide whether to install a traffic light in your hometown at a cost of $10,000. If the traffic light reduces the risk of fatality by 0.5 percent and the value of a human life is about $10 million, you should

a. install the light because the expected benefit of $50,000 is greater than the cost.

b. install the light because the expected benefit of $20,000 is greater than the cost.

c. not install the light because the expected benefit of $10,000 is only equal to the cost.

d. not install the light because the expected benefit of $5,000 is less than the cost.