A linear programming problem where the objective is to find the best mix of ingredients for a product to meet certain specifications is called:

a. a resource-allocation problem.

b. a blending problem.

c. a cost-benefit tradeoff problem.

d. a mixture problem.

e. None of the above.

Using techniques to test the initial versions of a model to identify errors and omissions is called:

a. model validation.

b. model enrichment.

c. model enhancement.

d. model debugging.

e. None of the above.