Which of the following is a general name for a species of azaleas?

The designation "Rhododendron sp." serves as a general name for a species of azaleas because it uses the abbreviation "sp." which indicates an unspecified species within the Rhododendron genus. Azaleas are part of this genus, and the term "sp." is commonly utilized in botanical nomenclature to refer to a member of a genus when the exact species is not identified or when discussing multiple species collectively.

In this instance, while "Rhododendron catawbiense" refers to a specific species of rhododendron that is known for its robust characteristics, it does not fulfill the requirement for a general name. Similarly, "Sarcococca hookeriana" is an entirely different genus and not related to azaleas, and "Syringa vulgaris" is commonly known as the lilac, which is also distinct from the azalea family. Therefore, "Rhododendron sp." is the appropriate choice as it effectively encompasses the various species within the azalea category without specifying one in particular.