Which of the following is MAXIMUM distance for 50 micron multimode fiber at 4Gb?

Which of the following is MAXIMUM distance for 50 micron multimode fiber at 4Gb?

A.
10 meters (32.8 feet)

B.
175 meters (574 feet)

C.
800 meters (2624.7 feet)

D.
2 kilometers (1.24 miles)