Contestants may wear ________ on their feet for weigh-in to protect from foot disease.

The correct answer is low-cut socks that fit below the ankle because they provide essential protection for the feet during weigh-ins without being cumbersome. Wearing socks helps to reduce the risk of foot diseases, such as athlete's foot or other fungal infections, that can be contracted in communal areas. Low-cut socks are preferable as they are lightweight and allow the wrestler to maintain the appropriate weight required for competition while still safeguarding their feet.

Heavy socks and thin footies could potentially interfere with the accurate weight measurement, as they may add unnecessary weight. Open-toed sandals do not provide adequate coverage or protection and could expose the wrestler's feet to contaminants in a weigh-in environment. Thus, low-cut socks strike the right balance between protection and compliance with weigh-in requirements.