The question asks the student to identify the only anthropoid ape to be found in India. Anthropoid apes are a group of primates that includes gibbons, great apes, and humans.

Option 1, the Hanuman monkey, is incorrect because it is not an ape, but a monkey, specifically a type of langur.

Option 2 is about the lion-tailed macaque of Western Ghats. While this is a primate, it`s a kind of monkey, not an anthropoid ape.

Option 3 suggests the slow loris of Assam, but slow lorises are prosimians, not anthropoid apes. They are in fact among the most primitive of primates.

Option 4, the white-browed gibbon of Assam is the correct answer. Gibbons, including the White-Browed Gibbon, are in fact a type of anthropoid ape, and the only such ape to be found in India. Thus, the correct answer is 4, the white-browed gibbon of Assam.