I would disagree noon-- B, to me, sounds incompatible with the Biologists claim. As Stopping Deforestation --> Extinct Koalas.

Claim of the Biologist; Forest continuing to disappear at its current rate --> Koalas approach Extinction.

Claim of Politician; all that is needed --> Stop Deforestation --> Save Koalas

Slowing Deforestation (slower rate) --> Save Koala.

Is consistent with the Biologist claim, but gives an alternative to the Politicians claim of "all that is needed is to stop deforestation" showing inconsistency with Politicians claim.