Zero price causes overconsumption and rationing need

Steps:

• Identify health care as a private good with positive marginal cost.
• Apply law of demand: zero price increases quantity demanded beyond efficient level.
• Recognize overconsumption leads to scarcity and inefficiency.
• Conclude rationing is required to allocate limited supply.

Why D is correct:

• Law of demand states lower price raises quantity demanded; at zero price, demand exceeds supply, causing overconsumption and necessitating rationing.

Why the others are wrong:

• A: No deduction possible from blank option.
• B: Health care is rival in consumption, as one person's use reduces availability for others.
• C: Zero price causes overconsumption, not under-supply; government funding may fund it but doesn't prevent excess demand.

Final answer: D