Concept:The farmhouse is best placed on high elevation to ensure proper drainage and to stay away from animal waste and odours.
Explanation:A fish pond requires low-lying land so that water can be retained easily.
A pigsty should be situated downhill and downwind from the farmhouse to prevent unpleasant smells from reaching the living area.
A processing shed generally needs level ground for easy operations and movement of materials.
High elevation provides a clean, dry, and healthy environment for the farmhouse.
Therefore, among the given options, the structure that should be located on high elevation is the farmhouse.
Answer:C. farmhouse