How dose having an EIGRP feasible successor speed up convergence?

How dose having an EIGRP feasible successor speed up convergence?
A . EIGRP sends quires only if there is a feasible successor, which decreases the number of routers that are involved in convergence.
B . EIGRP immediately installs the loop-free alternatives path in the RIB
C . EIGRP preinstalls the feasible successor in the RIB in all cases which traffic to switch more quickly
D . EIGRP sends queries only if there is not a feasible successor which causes less control traffic to complete with data.

Answer: B