Concept:Market gardening is the intensive, small-scale cultivation of high-value crops such as fruits, vegetables, and flowers for fresh, local sale.
Explanation:The description mentions small-scale farming with very high yields per hectare.
It also focuses on fruits, vegetables, and flowers.
The produce is sold fresh, which is a key feature of market gardening.
It is commonly practised in urban communities where demand for fresh produce is high.
Mixed farming combines crops with livestock, sericulture is silk production, and viniculture is grape cultivation for wine.
Therefore, the given description matches market gardening exactly.
Answer:C. market gardening.