$(1)$ 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 $\underline C\%$.

• A
  $A-25\%, B-2\%, C-30\%$
• B
  $A-50\%, B-4\%, C-30\%$
• C
  $A-50\%, B-4\%, C-60\%$
• D
  $A-25\%, B-2\%, C-60\%$