If We're Interested in Conserving Global Biodiversity, Why Is the Fact

If we're interested in conserving global biodiversity, why is the fact than tropical rainforests are shrinking dramatically especially bad?

A) Rainforests occupy a lot of territory so if they're shrinking, many species are being lost.
B) Rainforests are one of the most highly biodiverse ecosystems on Earth, so if they're being lost, many species are being lost.
C) Unlike most other habitats, it's very difficult to create manmade rainforests.
D) Rainforests are highly productive, and it's not good to lose that productivity globally.
E) It's not particularly bad. Every habitat on Earth is equally valuable for biodiversity.