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.
