Cotton can thrive well in the mangrove areas if the land is sufficiently drained. Mangrove areas are characterized by their saline and waterlogged soil which makes it difficult for most crops to grow, including cotton. However, cotton can tolerate a certain level of salinity if the soil is well-drained. This allows for proper aeration of the roots and prevents waterlogging which can lead to root rot. Additionally, proper drainage helps to reduce the concentration of salt in the soil, making it more conducive for cotton growth. The other options, such as applying appropriate fertilizer, lower intensity of sunshine, or controlling white flies, do not necessarily address the issue of soil drainage and may not guarantee cotton growth in mangrove areas.