The correct answer is (a) Great Indian Bustard, Musk Deer, Red Panda, and Asiatic Wild Ass.

The Great Indian Bustard is a large bird found in India and Pakistan that is critically endangered, with only a few hundred individuals remaining in the wild.

The musk deer is a small deer found in the Himalayan region that is also critically endangered, due to habitat loss and poaching.

The red panda is a small carnivorous mammal found in the Himalayan region that is endangered due to habitat loss and poaching.

The Asiatic wild ass, also known as the onager, is a species of horse found in parts of Asia that is endangered due to habitat loss and poaching.