Subsistence farming relies on family labor over capital investment

Steps:

• Define subsistence farming as producing food mainly for family consumption, not surplus for sale.
• Recognize that in developing countries, this often involves limited resources and technology.
• Link high population involvement to low mechanization, favoring manual methods.
• Conclude that capital-intensive production (e.g., machinery) is improbable due to cost barriers.

Why B is correct:

• Subsistence farming, by definition, uses minimal capital inputs like tools or equipment, relying instead on abundant family labor to keep costs low.

Why the others are wrong:

• A: Families may face shortages from poor yields or weather, not guaranteeing self-sufficiency.
• C: Efficiency is not assured; methods are often traditional and low-yield without modern inputs.
• D: Little surplus exists for trade, leading to minimal commercial exchange.

Final answer: B