Which of the following best explains why market prices are useful to a financial manager when performing a cost-benefit analysis?

a- They can be evaluated to determine whether the market in which the manager exchanges goods and services offers true value.

b- They can be used to convert different services and commodities into equivalent cash values which can be compared.

c- They can be used to determine how much an asset can be sold for.

d- They allow all commodities and services to be assigned a fixed and unchanging value.