Which of the following is NOT true regarding competitive markets?

The impact of an increase in the price of a particular good is illustrated as a

A) leftward shift in its demand curve. B) rightward shift in its demand curve. C) movement upward and to the left along its demand curve. D) movement downward and to the right along its demand curve. E) rightward shift in its demand curve and a movement upward and to the left along its demand curve.

When the errors are heteroskedastic, then

A) WLS is efficient in large samples, if the functional form of the heteroskedasticity is known. B) OLS is biased. C) OLS is still efficient as long as there is no serial correlation in the error terms. D) weighted least squares is efficient.