What best describes a symbiotic relationship?

A symbiotic relationship is best described as an interaction between two organisms that is beneficial to at least one. This type of relationship can take various forms, including mutualism, where both organisms benefit; commensalism, where one benefits and the other is neither helped nor harmed; and parasitism, where one organism benefits at the expense of the other.

Understanding this definition highlights the key aspect of symbiosis: the close association between organisms, which often leads to significant impacts on their biology and ecology. In contrast, relationships characterized by competition for resources or harmful interactions do not fit within the definition of symbiosis, as these do not involve mutual benefits or positive engagement between different species. Thus, option B accurately captures the essence of what defines a symbiotic relationship.