Biology

The correct answer is: B. Two species living together in a close, long-term relationship where at least one benefits.

Explanation:

Symbiosis refers to a close and often long-term relationship between two different species that live in close physical proximity to each other. The relationship can be beneficial to both, beneficial to one and neutral to the other, or even harmful to one of the species involved.

There are three main types of symbiosis:

1. Mutualism: Both species benefit from the relationship.

Example: Bees and flowers (bees get nectar, and flowers get pollinated).

2. Commensalism: One species benefits, and the other is neither helped nor harmed....