You have been tasked with designing an Ethernet network. Your client needs to implement a very high-speed network backbone between campus buildings, some of which are around 300 meters apart. Multi-mode fiber optic cabling has already been installed between buildings. Your client has asked that you use the existing cabling.
Which Ethernet standard meets these guidelines? (Choose two.)

a.10GBaseSR
b.10BaseFL
c.10GBaseER
d.1000BaseSX
e.1000BaseT

a.10GBaseSR

d.1000BaseSX

Explanation:

In Computer Networking, The 1000BaseSX is a type of cabling standard used for deploying Gigabit Ethernet networks. The SX in 1000BaseSX denotes short, and it implies that it's for use with transmissions having short-wavelength over short runs of fiberoptic cabling in a Gigabit Ethernet networks.

The SR in 10GBaseSR denotes short-range, it is exclusively used for multi-mode fiberoptic medium that uses 850nm lasers having LC duplex connector and DDM with a maximum transmission distance of 300meters in a Gigabit Ethernet networks.

that would be my answer.