Final answer:
An example of a non-symbiotic facultative mutualism would involve organisms benefiting from each other, but not necessarily depending on one another for survival. In this case, the correct answer is Oxpeckers and large mammals.
So, the correct answer is c) Oxpeckers and large mammals.
Step-by-step explanation:
Oxpeckers, or 'tick birds', feed on ticks, blood and dander on large mammals; this is beneficial for the mammals as well, as it helps them stay free from parasites. The mammals benefit from the pest control, while oxpeckers benefit from a food source. Although these two species benefit from their association, it is not obligatory for their survival, making it a facultative mutualistic relationship.
In contrast, the other options, such as mycorrhizal fungi and plants, lichens (a partnership between fungi and photosynthetic organisms like algae), and nitrogen-fixing bacteria and legumes, involve more integrated and often obligatory mutualistic relationships.
So, the correct answer is c) Oxpeckers and large mammals.