What is an implication of using route reflectors in an iBGP topology?

Route reflection limits the total number of iBGP routers.

Route reflection causes traffic to flow in a hub-and-spoke fashion.

The manipulation of BGP attributes is not supported on the other routers than the route reflectors.

Route reflectors can create routing loops when more than one router reflector is used in the same cluster.

Multipath information is difficult to propagate in a route reflector topology.