What is the main difference between green tea and black tea?

The primary distinction between green tea and black tea lies in their processing methods. Green tea is not fermented; instead, the leaves are quickly steamed or pan-fired to prevent oxidation, preserving the green color and fresh flavor. On the other hand, black tea undergoes full oxidation, which not only darkens the leaves but also intensifies the flavors. This key difference in processing is what fundamentally differentiates the two types of tea, influencing their taste, color, and health benefits.

The other choices presented do not accurately describe the differences. Black tea is, in fact, fermented, which is the opposite of what option A states. Additionally, while some green teas may be flavored with fruits or other ingredients, it is not a defining characteristic of all green teas. Black tea can contain varying levels of caffeine depending on the type and brewing method, but it is not necessarily a universal trait that distinguishes it from green tea.