When a plant is facing a very high risk of extinction in the wild in the near future and needs urgent measures to save it from extinction, which of the following the most desirable approach?

When there are situations where an animal or plant is endangered or threatened (organisms facing a very high risk of extinction in the wild in the near future) and needs urgent measures to save it from extinction, ex situ conservation (e.g., seed bank, cryopreservation) is the desirable approach.