What Was a Requirement of the Fugitive Slave Act,part of the Compromise

What was a requirement of the Fugitive Slave Act,part of the Compromise of 1850?

A) Any runaway slave who reached the North would be considered free.
B) Slave commissioners received $10 for setting a slave free and $5 for returning a slave to his or her master.
C) Slave owners needed three witnesses in order to claim a runaway.
D) All citizens were expected to assist officials in apprehending runaway slaves.