Which of the following is a disease that is constantly present in a particular population or region, spreading permanently within that small area?

1.
Statement (A): The cenotaphs of Tehla (Alwar) are famous for their vibrant carvings.
Reason (R): The cenotaphs here depict scenes of daily life carved on the stones.
Statement (A) is true, as Tehla cenotaphs are known for their intricate and lively carvings. Reason (R) is also true and provides the explanation for why the carvings are considered vibrant and famous. Therefore, both the statement and the reason are correct, and the reason correctly explains the statement.
The correct option is (A).

2.
Conservation tillage aims to minimize soil disturbance and maintain a significant amount of crop residue on the soil surface to protect it from erosion and improve soil health. The generally accepted guideline for effective conservation tillage is to maintain at least 30% crop residue cover on the soil surface after planting.
The correct option is (A).

3.
Legume vegetables contain certain anti-nutritional factors that can reduce their nutritional value. Among the given options, trypsin inhibitors are well-known anti-nutritional factors found in legumes. They interfere with protein digestion by inhibiting the activity of the enzyme trypsin in the digestive system.
The correct option is (A).

4.
A disease that is constantly present in a particular population or region, spreading permanently within that small area, is