Supply tends to be more elastic in the short run and more inelastic in the long run

How does a perfect market influence output?

(A) Different firms each strive to make more goods and capture more of the market. (B) Different firms make different amounts of goods, but some make a profit and others do not. (C) Each firm makes its output as large as possible even though some goods are not sold. (D) Each firm adjusts its output so that its costs, including profit, are covered.

The t-statistic is calculated by dividing

A) the OLS estimator by its standard error. B) the slope by the standard deviation of the explanatory variable. C) the estimator minus its hypothesized value by the standard error of the estimator. D) the slope by 1.96.