The sharp, inch-long thorns of the crown-of-thorns sea star are its spines. these spines, unlike those of most other sea stars, contain a potent toxin. if it were discovered that crown-of-thorns sea stars do not make this toxin themselves, then the most likely alternative would be that this toxin is
a) derived from the nematocysts of its prey
b) absorbed from the surrounding seawater
c) an endotoxin of cellulose-digesting bacteria that inhabit the sea star's digestive glands
d) injected into individual thorns by mutualistic corals which live on the aboral surfaces of these sea stars