Final answer:
Of the options provided, visible blood in the ear canal is an objective finding and not a subjective one, as it can be confirmed by visual inspection.
Step-by-step explanation:
Subjective findings are those that are reported by the patient and cannot be measured or confirmed independently. These findings include sensations such as a feeling of impending doom, a persistent dull headache, and acute and severe nausea, which are all experienced by the patient and difficult to quantify precisely. However, one option among the choices given is not subjective but rather objective: A) visible blood in the ear canal is an objective finding because it can be seen and confirmed by a clinician, independent of the patient's personal feelings or reports.