How would you best describe the condition of Rebecca's left ear?

The condition described by the answer choice, which indicates a white or red coloration, reduced mobility, opacity, and bulging of the eardrum, is characteristic of acute otitis media (AOM). In AOM, inflammation and infection within the middle ear cause these hallmark signs. The appearance of a bulging eardrum signifies that pressure has built up from fluid accumulation behind the eardrum, often due to infection.

Alongside the erythema (redness), which reflects irritation and inflammation, an opaque appearance indicates that the normal transparency of the eardrum is lost due to infection or fluid presence. Reduced mobility can be assessed with pneumatic otoscopy, where the eardrum demonstrates little to no movement in response to changes in air pressure, further corroborating the severity of the condition. This combination of findings is critical in making an accurate diagnosis and subsequently determining the appropriate treatment for the patient experiencing these symptoms.