If the price rises and the total amount consumers spend on the good remains unchanged, then demand must be

Which of the following happens when an economy's labor demand curve shifts to the left without any change in its labor supply curve assuming all else equal?

A) The equilibrium wage rate rises. B) The output of the economy rises. C) The aggregate price level falls. D) The unemployment rate rises.

Jill runs a factory that makes lie detectors in Little Rock, Arkansas. This month, Jill's 34 workers produced 690 machines. Suppose Jill adds one more worker and, as a result, her factory's output increases to 700 Jill's marginal product of labor from the last worker hired equals ________.

A) 10 B) 20 C) 690 D) 700 E) None of the above answers is correct.