The main characteristic of biodiversity hotspots is/are

A biodiversity hotspot is defined by both a high threat from human activity and a set share of endemic species.

The threat from human beings alone is only one of the two required criteria.

A region with a specified percentage of endemic species alone is only the other single criterion.

Since both conditions together define a hotspot, neither being correct does not apply.

The standard threshold is at least 1,500 endemic plant species plus loss of most original habitat.

The Western Ghats and the Himalaya are among India's recognised biodiversity hotspots.