Upon which of the following industries is a restrictive monetary policy likely to be most effective?

You want to purchase two umbrellas. The price is $40 per umbrella, 2 for $60, 3 for $75. What will be the marginal cost to you of buying a third umbrella?

A) $75 B) $25 C) $20 D) $15 E) $10

Agricultural extension refers to

a. increasing the amount of land on which crops are grown b. helping farmers understand and use new techniques c. increasing the number of workers on the land d. increasing the range of inputs used by farmers e. none of the above