4. [25 Points] Suppose that a firm has the production function f (z1, Z2) = min {3z1, z2}. (a) [4 Points] Illustrate this production technology's isoquants. (b) [5 Points] Show that this production technology satisfies the no-free lunch property. (c) [5 Points] Show that this production technology satisfies the free disposal property. (d) [5 Points] Does this production technology have increasing, decreasing or constant returns to scale? (e) [6 Points] Find the technical rate of substitution (TRS) at inputs (z1, Z2) = (1, 6), (21, 22) = (2, 6), and (z, z2) = (6, 6)