The following is correct about a probabilistic indicator for bacterial identification, EXCEPT that

A) it requires a predefined database of known bacteria.
B) numerous strains of each species in well-studied habitats must be isolated in pure culture and tested for a defined number of traits.
C) it is based on yes/no choices that successively narrow down the identification of a taxon.
D) it only works if the bacterial isolate coincides with a member of a predefined database.
E) fractions of positive results for certain traits are noted as the probability of obtaining a positive result.