Five Species of Ants Can Be Found on Aspen Sunflowers

Multiple Choice

Five species of ants can be found on aspen sunflowers (Helianthella quinquenervis) , which live in wet mountain meadows of the Rocky Mountains. The aspen sunflowers provide nectar to the ants in special structures called extrafloral nectaries. The ants, in turn, protect the sunflowers from other insects. The ants, however, are not found solely on the sunflowers-they can be found tending aphids on other flower species and collecting nectar from other species as well. This, then, is an example of a(n) :

A) obligate mutualism.
B) obligate antagonism.
C) facultative mutualism.
D) facultative antagonism.
E) None of the answer options is correct.