21. According to a finding Benin's import of iron and steel is 3.15% and of mechanical appliances is 7.17% of its total imports in 2019. In the wake of COVID-19 and the economic slowdown following the same Benin is contemplating the reviewing of its foreign trade. The production function of Benin for two commodities could be represented as f (iron, machine) = max{ iron, machine}. a) Does the production have a convex or a non-convex input requirement set? b} What is the conditional factor demand function for iron? c) What is the cost function? d} Show the graphical representation ofthe country's preference