The correct answer is option 2, the Mediterranean region. This region is known for being an important supplier of citrus fruits.
Option 1, the equatorial region, is not typically known for citrus fruit production. The equatorial region is characterized by a hot and humid climate, which is not ideal for growing citrus fruits. Citrus fruits thrive in a slightly cooler temperature range.
Option 3, the desert region, is also not a major supplier of citrus fruits. The desert climate is extremely arid and lacks the necessary moisture for citrus cultivation.
Option 4, the sub-humid region, could potentially be a source of citrus fruits, but it is not as significant as the Mediterranean region. The Mediterranean climate, characterized by mild winters and warm summers, provides an ideal environment for citrus tree growth and production.
In conclusion, while there may be other regions that grow citrus fruits, the Mediterranean region is recognized as an important supplier. Its climate and geographical conditions are highly suitable for cultivating citrus fruits.