Which best describes an ecological community? a.intraspecific competition of members of a brook trout population inhabiting a stream during a given year, b. interactions of all plant and animal species inhabiting a 2 hectare section of forest, c. material cycling and energy tranformations between biotic and abiotic compounds of an open meadow, d. various species of barnacles competing for resources in an intertidal zone or e. interactions of various plant and animal species in one park , excepting the decomposers?