In the United States from 1981 to 2015, deaths from which of the following increased?

The assumption that a perfectly competitive industry has many sellers, each selling an identical product, leads to the conclusion that

A) consumers get to see a variety of outputs. B) there are many buyers. C) the economic profit will be positive in the long run. D) firms are price takers.

Over the past several years, the earnings gap between high-skilled and low-skilled workers has (i) narrowed because the demand for unskilled labor has risen over time relative to the demand for skilled labor. (ii) widened because the demand for skilled labor has risen over time relative to the demand for unskilled labor. (iii) narrowed because the supply of unskilled labor has risen over time

relative to the supply of skilled labor. (iv) widened because the supply of skilled labor has risen over time relative to the supply of unskilled labor. a. (i) only b. (ii) only c. (i) and (iii) only d. (ii) and (iv) only