What type of seal is used in the gearbox of a gas turbine engine?

Correct Answer: Option D — Carbon ring

Carbon ring seals are standard in gas turbine gearboxes due to their ability to withstand high rotational speeds and provide effective sealing with minimal friction. These self-lubricating rings maintain a tight clearance around the shaft, preventing oil migration and ensuring the gearbox remains pressurized and free of contaminants.