Question

\class one\ classifies which class of annelids?
class oligochaeta
class hirudinea
class polychaeta

Explanation:

In the classification of Annelids, "Class One" (a common way to refer to the first - named major class in some classification contexts) corresponds to Class Polychaeta. Polychaetes are one of the main classes of Annelids, characterized by having many chaetae (bristles) and often being marine organisms. Oligochaeta (like earthworms) and Hirudinea (leeches) are other classes of Annelids but are not referred to as "Class One" in this classification context.

Answer:

Class Polychaeta