What are the four major sources of emeralds?

The correct selection highlights the four major sources of emeralds, which are recognized for their quality and historical significance in the gemstone market. Colombia is widely celebrated as the premier source of emeralds, known for producing the finest quality stones with a deep, rich green hue. Zambia and Brazil are also crucial sources, contributing significantly to global emerald production with notable variations in color and clarity.

Zimbabwe can be included as an emerging source, especially in the past few decades, although its reputation is not as established as the others. This combination reflects the most relevant origin points in the context of emerald mining and trade.

In contrast, other options contain countries that are not recognized as major sources of emeralds or include incorrect combinations. For example, Australia is not traditionally known for emerald production, and although India has some emerald deposits, it does not rank among the top producers compared to the selected countries in this answer. These factors contribute to clarifying why option B effectively lists the primary sources of emeralds.