Answer:
A. Animals in a rainforest can be difficult for scientists to find.
Step-by-step explanation:
According to the article about the "Rainforest" you've attached, a reason why a healthy habitat is harder to spot in a rainforest is due to the "density of the rainforest." This density makes it harder for the scientist to find the animals because the animals remain hidden in it. Animals can easily adapt to such niche by camouflaging or doing other similar strategies to remain hidden. This makes it harder for the scientists to tell the well-being of the animals.