Correct option is A
Marginal costing focuses on analyzing the costs and benefits of each individual product or activity separately. It helps in decision-making by considering the incremental costs and revenues associated with different options. The valid decision choices in relation to marginal costing are: (A) Costing 'special' or "one off opportunities. (B) Deciding whether to make or buy a product. (D) Choosing between competing alternative actions. (E) Employing a penetration or destroyer pricing strategy. "Most appropriate technique because of the application of more automation in the industry" is not directly related to marginal costing. Marginal costing is a cost accounting technique that primarily focuses on the distinction between fixed costs and variable costs, and it does not depend on the level of automation in the industry