• Time Horizons in Production Economics:
• Intermediate Run: A decision-making time horizon of intermediate duration where many inputs (e.g., labor, variable machinery, operating capital, livestock numbers) can be adjusted and treated as variable, but certain fixed durable plant/land structures remain fixed.
• Short Run: A production period so brief that at least one primary input (e.g., land, permanent farm buildings) is strictly fixed, while only operating inputs (seeds, fertilizers, diesel) can vary.
• Long Run: A planning horizon sufficiently long that all inputs and factors of production become variable; firm scale can be altered freely and no fixed costs exist.

Correct option: (4) Intermediate run