2. Choice, alternative, option, preference all suggest the power of choosing between things. Choice implies the opportunity to choose: a choice of evils. Alternative suggests that one has a choice between only two possibilities. It is often used with a negative to mean that there is no second possibility: to have no alternative. Option emphasizes free right or privilege of choosing: to exercise one's option. Preference applies to a choice based on liking or partiality: to state a preference. 9. See fine¹.

Did you mean biocenosis?