Which of the following decision choices are valid in relation to marginal costing?

(A) Costing 'special' or 'one-off opportunity.

(B) Deciding whether to make or buy a product.

(C) Most appropriate technique because of the application of more automation in the industry.

(D) Choosing between competing alternative actions.

(E) Employing a penetration or destroyer pricing strategy.

Choose the correct answer from the options given below: