Correct Option: D. Remove sprouts and rotten tubers Explanation of the Correct Answer: Yams are a staple food in many parts of the world, and proper storage is crucial to maintain their quality and extend their shelf life. When yams are stored in a barn, they can undergo various changes due to environmental conditions and biological processes. Inspecting yams at least once a week is essential for several reasons, primarily to remove sprouts and rotten tubers.

1. Sprouting: Yams, like many other tubers, can begin to sprout if they are stored for an extended period. Sprouting occurs when the tuber senses favorable conditions for growth, such as moisture and warmth. While sprouted yams are not necessarily harmful, they can lose nutritional value and flavor. Additionally, the energy that the yam would use to grow new shoots is taken from the tuber itself, leading to a decline in quality. Regular inspections allow for the early removal of sprouted yams, ensuring that the remaining tubers maintain their quality.
2. Rotting: Yams can also develop rot due to various factors, including excess moisture, physical damage, or fungal infections. Rotten tubers can release ethylene gas, which can accelerate the spoilage of nearby healthy yams. By inspecting the stored yams weekly, any rotten tubers can be identified and removed promptly, preventing the spread of decay and preserving the overall quality of the stored yams.
3. Overall Quality Maintenance: Regular inspections help maintain the overall quality of the stored yams. By removing both sprouts and rotten tubers, the remaining yams can be kept in optimal condition for a longer period, reducing waste and ensuring that they remain safe for consumption.

Explanation of Why Other Options Are Incorrect:

• Option A: Remove irregular shaped tubes: While it is true that some consumers prefer uniformity in the shape of yams, the primary reason for weekly inspections is not to remove irregularly shaped tubers. Irregular shapes do not necessarily indicate spoilage or a decline in quality. Therefore, this option is less relevant to the main goal of maintaining the health of the stored yams.
• Option B: Control termite attack: Termites are not typically a significant threat to stored yams in a barn setting. While pests can be a concern in agricultural storage, the primary focus of weekly inspections is on the condition of the yams themselves rather than controlling termite populations. This option does not address the immediate issues of sprouting and rotting, making it a weaker choice.
• Option C: Prevent mouldiness in yam: While preventing mouldiness is important, it is a secondary concern compared to the immediate need to remove sprouts and rotten tubers. Mould can develop as a result of moisture and poor air circulation, but the act of removing sprouted and rotten yams directly addresses the quality and safety of the remaining tubers. Therefore, this option does not encompass the full scope of the inspection's purpose.

Summary for Revision:

• Inspect yams weekly to maintain quality and extend shelf life.
• Key reasons for inspection include removing sprouts and rotten tubers.
• Sprouting reduces nutritional value and flavor; rotting can spread decay.
• Other options (irregular shapes, termite control, mouldiness) are less relevant to the primary goal of maintaining yam quality.