When marginal product is negative, the slope of the total product curve must be negative.?

In the economic way of thinking, bald eagles are a scarce good. Thus,

A) the bald eagle population can be maintained at no cost. B) the bald eagle population should be maintained at any cost. C) there are substitutes for bald eagles. D) there are no substitutes for bald eagles. E) economists don't like bald eagles.

The phase in the business cycle in which real GDP begins to decline is called a

a. trend b. peak c. downturn d. recovery e. trough