Which of the following is $NOT$ a criterion for identifying a biodiversity hotspot?

The Amazon rain forest is estimated to produce what percentage of the total oxygen in the Earth's atmosphere through photosynthesis (in $\%$)?

The ................ have a greater amphibian species diversity than the .......

Beta diversity is the diversity:

Approximately $.........$ plant species are used by indigenous people around the world in traditional medicines. (in $,000$)

$(1)$ More than $\underline A\%$ of the drugs currently sold in the market worldwide are derived from plants.
$(2)$ Although all the biodiversity hotspots put together cover less than $\underline B\%$ of Earth's land area,the number of species they collectively harbour is extremely high,and strict protection of these hotspots could reduce the ongoing mass extinction by almost $\underline C\%$.