How does the current "Sixth Extinction" differ from the previous epis…

The correct answer is Option (4) → It is much faster in rates of species loss, and human activities are responsible for the faster rates.

Fossil records show five earlier episodes of mass extinction of species, long before humans appeared. The loss of species going on today is called the ‘Sixth Extinction’. It differs from the earlier ones in its rate and in its cause.

Option (1) It is slower in rates of species loss. — Incorrect. The present loss is not slower. Species are now being lost 100 to 1,000 times faster than in pre-human times.

Option (2) It is unrelated to human activities. — Incorrect. Human activities are the main cause of the present extinctions, through habitat loss, over-exploitation, alien species invasions and co-extinctions.

Option (3) It is characterized by random extinctions across taxa. — Incorrect. The book does not describe the present extinction as random. It traces the losses to human activities, so they are not chance events spread across groups.

Option (4) It is much faster in rates of species loss, and human activities are responsible for the faster rates. — Correct. The current extinction rates are estimated to be 100 to 1,000 times faster than in pre-human times, and human activities are responsible for the faster rates.

NCERT Extract:
Loss of Biodiversity – “… From a study of the history of life on earth through fossil records, we learn that large-scale loss of species like the one we are currently witnessing have also happened earlier, even before humans appeared on the scene. During the long period (> 3 billion years) since the origin and diversification of life on earth there were five episodes of mass extinction of species. … The difference is in the rates; the current species extinction rates are estimated to be 100 to 1,000 times faster than in the pre-human times and our activities are responsible for the faster rates.”