What feature(s) of a daymark is (are) used to identify the beacon upon which it is mounted?

Correct Answer: Option A — Color and shape

Daymarks are identified primarily by their color and shape, which convey their specific lateral or non-lateral significance. These visual characteristics allow mariners to distinguish between port, starboard, preferred channel, and safe water marks, ensuring proper navigation as defined in the USCG Light List and navigation manuals.