Question

hybrid vehicle general safety concerns
hybrid vehicle high voltage circuits
the electric drive system of a hybrid vehicle contains high voltage that is dangerous to the human body. for example, many hybrids have an hv (high - voltage) battery output voltage of more than 200 vdc. the inverter then converts the dc voltage into around 500 vac or more! therefore you must refer to the manufacturer service information for detailed operation instructions and wear appropriate personal protective equipment when working on hybrid vehicles.
basic precautions

• always wear hv rated gloves when working around the hv battery.
• always disable hv system and wait the required time for the capacitors to drain, before working around any hv cables.
• always follow manufacture specific instructions for disabling hv system.
• before checking fluids or changing oil on a hybrid, make sure the ready light on the instrument panel is off. if the ready light is on, the engine may start at anytime without notice.
• place warning labels and signs around a hv vehicle that has been immobilized for service to warn others of the potential danger.

compare to a normal vehicle, what is the unique hazard a hybrid has?
special oil used by hybrid vehicles.
special fuel used by hybrid vehicles.
high voltage in the battery and inverter circuits.

Explanation:

The text emphasizes that the electric drive system of hybrid vehicles has high - voltage components like an HV battery with output over 200 VDC and an inverter that can convert to around 500 VAC or more, which is a unique hazard compared to normal vehicles. It does not mention special oil or fuel as unique hazards.

Answer:

High voltage in the battery and inverter circuits.