Which of the following is rated for speeds over 800Mbps?

Coaxial cable is used for cable internet and TV signals and does not have a standardized Ethernet speed rating that reaches or exceeds 800 Mbps in typical LAN deployments.

DB-9 is a 9-pin serial connector used for RS-232 communications, which operates at very low speeds (typically under 1 Mbps) and is unrelated to high-speed Ethernet.

CAT6 (Category 6) cable operates at up to 250 MHz and supports speeds of 1 Gbps at 100 meters and up to 10 Gbps at distances up to 55 meters. This makes it definitively rated for speeds well above 800 Mbps, outperforming older cable categories in both speed and frequency headroom.

CAT5e supports up to 1 Gbps but is rated at 100 MHz, offering less headroom and performance than CAT6, and is considered the lower-tier option between the two.