In the market for oranges, availability of substitutes limits a single seller's power over price

As the stock of a depletable resource falls, its user cost

A) rises. B) falls. C) is unchanged, but its price rises. D) is unchanged, but the extraction cost rises. E) is unchanged, but its true cost rises.

If the law of increasing opportunity costs is operable, and currently the opportunity cost of producing the 101st unit of good X is 5Y, then the opportunity cost of producing the 201st unit of good is X is most likely to be

A) less than 5Y. B) more than 1/5Y but less than 5Y. C) more than 5Y D) less than 1/5Y but more than zero.