The answer that best describes why deforestation in tropical rainforests is a concern is:
Deforestation can cause a loss of biodiversity.
Tropical rainforests are home to a vast array of plant and animal species, many of which are not found anywhere else on Earth. Deforestation leads to habitat destruction, which in turn can result in the extinction of these species and a significant reduction in biodiversity. This loss can disrupt ecosystems and the services they provide, which is a critical concern for environmental stability and human well-being.