The correct answer is option 3, Malaysia. The Equatorial region, also known as the tropical rainforest region, is known for its abundant rainfall and lush vegetation. Rubber is a major cash crop cultivated in this region due to its favorable climate and soil conditions. While rubber plantations can be found in various parts of the Equatorial region, Malaysia is particularly well known for its well-developed rubber plantations.
Option 1, the Amazon basin, is not the most suitable location for rubber plantations as the region is mainly covered by dense rainforests and does not have a significant history of rubber cultivation.
Option 2, Indonesia, is another important rubber producing country in the Equatorial region. However, Malaysia has a more established and developed rubber industry.
Option 4, Zaire basin (now known as the Democratic Republic of the Congo), is not renowned for rubber production.