The main difference between the ‘Sixth extinction’ and the previous five extinctions is that, the sixth extinction

The correct option is occurs at a faster rate.

Understanding the Sixth Extinction:
Earth has experienced five major mass extinction events in its geological history, mostly driven by natural phenomena such as asteroid impacts, volcanic activity, and major climate shifts.
The current ongoing extinction phase, often referred to as the Sixth Extinction or the Anthropocene Extinction, differs fundamentally from the previous five events in two primary ways:
1. Rate of Extinction: Scientists estimate that current species extinction rates are 100 to 1,000 times faster than the natural background extinction rates observed in the fossil record.
2. Anthropogenic Cause: Unlike the previous mass extinctions caused by natural disasters, the current extinction crisis is primarily driven by human activities, including habitat destruction, overexploitation, climate change, and pollution.

Evaluating the Options:
• mainly affects plants: Incorrect. The sixth extinction broadly impacts both plant and animal species across various ecosystems globally.
• occurs at a faster rate: Correct. The accelerated pace of species loss is the defining feature distinguishing the sixth extinction from historical mass extinctions.
• mainly occurs on islands: Incorrect. While island species are vulnerable, mass extinction is occurring across terrestrial, marine, and freshwater environments worldwide.
• is exclusive of human activities: Incorrect. Human activity is actually the primary driver of this current extinction event.