Final answer:
SATA (Serial ATA) is the power connector used to connect internal devices such as optical drives and hard drives to the motherboard.
Step-by-step explanation:
The type of power connector used to connect devices such as optical drives and hard drives is c) SATA (Serial ATA). While USB and HDMI are used for other types of connections, and VGA is predominantly used for video output, SATA is designed specifically for connecting internal drives like hard drives and optical drives to the motherboard, allowing for data transfer and electrical power to these devices.