Outward PPC shift from increased resources Steps:

• Production possibility curve (PPC) shows maximum output combinations of two goods with fixed resources and technology.
• Shift from O to L indicates outward movement, meaning greater productive capacity for both goods.
• Evaluate causes: changes in wants affect points on curve, not shape; recession reduces output inside curve; investment expands capacity; unemployed resources move from inside to on curve.
• Select option expanding frontier: more investment.

Why C is correct:

• Investment increases capital stock, shifting PPC outward per economic growth models like Solow, enhancing long-run production potential.

Why the others are wrong:

• A: Alters relative demand, rotating or moving along PPC, not shifting it.
• B: Lowers actual output, placing economy inside PPC without shifting boundary.
• D: Utilizes idle resources, moving from inside to on existing PPC, not expanding it.

Final answer: C