Thanks for your help. Could you please explain every option of this question in detail?

Consider an apple juice company whose marginal product of labor and marginal product of capital are respectively given by MPL (L, K) = 4 and MPK (L, K) = k for any input choice where L and K are the total labor and capital employed. The current input prices are w= 10 and r= 20, respectively. Suppose that the company currently hires (L, K) = (200,100) to produce 2000 units of output. Which of the following statements is true? The firm could lower its production cost by substituting a part of its current labor employment with capital. ver The firm has minimized its production cost at (L. K) = (200, 100). The marginal rate of technical substitution is (approximately) 1 at (L.K) = (200.100). The firm could lower its production cost by substituting a part of its current capital employment with labor