Which of the following could be a symptom of VHD?

Lethargy is a significant symptom of Viral Hemorrhagic Disease (VHD) in rabbits. When a rabbit is infected with VHD, it often shows signs of extreme fatigue and a lack of energy. This behavior can indicate that the rabbit is sick and not feeling well, as they may not be as active or responsive as they normally would be. Lethargy is a common reaction in animals dealing with severe health issues, including infectious diseases, and is a critical indicator for pet owners to be aware of when monitoring their rabbits for health problems.

Other symptoms related to VHD can include sudden death, difficulty breathing, and bleeding from various orifices. However, the options involving excessive grass eating, unusual play behavior, and bright-colored urine are not typical indicators of VHD and may suggest other health or behavioral issues that do not directly relate to this specific viral disease.