Consider a Firm That Seeks to Minimize the Cost of Producing

Consider a firm that seeks to minimize the cost of producing a given level of output. Which of the following statements is true?

A) In equilibrium, the rate of return on capital equals the wage rate.
B) In equilibrium, the wage rate equals the slope of the isoquant.
C) In equilibrium, the ratio of input prices equals the marginal rate of technical substitution.
D) In equilibrium, it will produce on the inelastic portion of its long-run labour demand curve.
E) In equilibrium, the rate of return on capital equals the slope of the isoquant.