Which land type is primarily designated for growing food and fiber?

Cropland is specifically designated for the production of food and fiber, making it the correct choice. It is an essential type of land use where various crops are cultivated, including grains, fruits, vegetables, and other agricultural products. This land type is typically enriched with nutrients and can be managed intensively to increase yields and support food security.

Parks and preserves prioritize conservation and recreation rather than agricultural use, while rangeland is primarily used for grazing livestock, which is different from crop production. Wetlands serve crucial ecological functions, such as water filtration and habitat for wildlife, and are not primarily utilized for agriculture. Therefore, cropland is the most appropriate classification for land primarily designated for growing food and fiber.