Read the passage carefully and choose the best answer to each question out of the four alternatives.
The elusive and charismatic snow leopard has lost its endangered status in the Red List of the International Union for Conservation of Nature, causing genuine worry among wildlife biologists, who believe this sends out the wrong signal to those working to protect it. If the argument for a downgrade to vulnerable status from endangered is that conservation actions have reduced the threat to the cat, there is an equally persuasive response on how little scientists know about its population health, given its remote habitat in the alpine zones of the Himalayas and trans-Himalayas. As a major range country, India has worked to protect these animals, and even launched a programme on the lines of Project Tiger for its conservation, covering 128,757 sq. km of habitat in Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh. There is also an upcoming international collaborative effort, the Global Snow Leopard and Ecosystem Protection Program, involving the countries that make up the range of this graceful animal. It is vital that this momentum should not be lost merely on account of the technicality that the estimated numbers have crossed the threshold for an 'endangered' classification, which is 2,500. If anything, studies on its vulnerability have to be intensified, and the task of monitoring its entire habitat of high mountains speeded up.
On what factor is the classification of a species decided?

Options

A. How critical that species is in the food web
B. Its population
C. Its habitat
D. On expert opinion

Answer

A