The production possibilities curve may shift outward as a result of a(n) a. increase in worker training courses. b. decrease in costs of production. c. increase in short run aggregate supply. d. decrease in short run aggregate supply. e. increase in consumer spending.

Statements A, B, C, and E will all cause shift of production possibilities curve outwards. This is because:

Statement A: Training of workers will mean improved skills and knowledge. This will in turn lead to increased productivity and may lead to efficiency and thus increased production.

Statement B: Decrease in cost of production will lead to production of more goods and thus the curve will shift outwards.

Statement C: Increase in short-run aggregate supply may mean supply of more raw materials to the production thus increased productivity.

Statement D: Increase in customer spending will mean increased demand and thus leads to shifting in supply. This leads to increased production.