Which example shows an ecosystem of organisms? a. a single monkey b. a group of tree monkeys c. a group of tree monkeys and a cluster of trees d. a group of tree monkeys, a cluster of trees, a pile of rocks, and a fierce wind

A single monkey is not an ecosystem

As ecosystem comprises of all the living and non living parts a community under study.

So if have define an ecosystem of which monkey is a part then we have to include the living organism like tress and monkey and the non living parts like rock and wind which affects the living organism.