The sum total of all the roles an organism plays in a habitat is referred...

Explanation

The question is asking about a term used to describe all the different roles an organism plays in its habitat. This term is known as the organism's niche. A niche is the way an organism fits into its environment and includes things like what it eats, where it lives, and how it interacts with other organisms. It's important to understand that a habitat and a niche are not the same thing. A habitat is simply the physical environment where an organism lives, while a niche is the organism's specific role within that environment. For example, a habitat for a bird might be a forest, but its niche could be eating insects, building nests in trees, and competing with other birds for food and territory. Understanding an organism's niche is important for understanding how it interacts with other organisms in the same habitat. So, to sum up, the sum total of all the roles an organism plays in its habitat is known as its niche. The correct option for this question is option D.