Final answer:
An endangered species is a species in imminent danger of extinction due to factors such as habitat loss, overexploitation, alien species, pollution, and disease. Protecting endangered species is crucial for conserving biodiversity and sustaining the earth's natural diversity. The answer is option B.
Step-by-step explanation:
An endangered species is a species that is in imminent danger of extinction throughout all or a significant portion of its range. It is determined by looking at data such as population size, trends in population size, and trends in the amount of habitat.
One of the leading causes of species endangerment is habitat loss, which can result in small, fragmented patches of habitat that put species at high risk of extinction. Other threats include overexploitation, alien species, pollution, and disease. The protection of endangered species is important for conserving biodiversity and maintaining the earth's natural diversity.