Final answer:
The poison dart frog lives in the understory layer of the Amazon rainforest, which is the natural habitat for many broad-leaved plants that are adapted to low light and are often used as ornamental indoor plants.
Step-by-step explanation:
The poison dart frog is an amphibian that is known to inhabit the understory layer of the Amazon rainforest. This layer contains a diverse array of life, due to its location above the forest floor and beneath the canopy. This is also the layer where you can find broad-leaved plants that have adapted to low light conditions, much like the environment found indoors which makes many of these plants suitable as ornamental indoor plants.
The attributes of the understory—the area that supports the growth of poison dart frogs—include adaptation to limited light and moisture, resembling conditions often found indoors. These adaptations hint at why many tropical plants from this layer make popular houseplants; they have evolved to thrive in environments with low light (such as 'C' option suggesting with their broad leaves, these plants are adapted to grow in low light, like that usually found indoors) and are already accustomed to the climate of typical indoor settings.
Unfortunately, despite the rich biodiversity, tropical rainforests like the Amazon struggle with nutrient retention in their soils, as the high levels of rainfall can leach nutrients away. However, the intricate structure of these forests, with their multiple layers, still supports immense biodiversity with each layer providing distinct habitats for a plethora of animal and plant species, including the poison dart frog.