Which term describes they the way rights granted to a container object flow down to all objects within the container?

Filtering - specifically an Inherited Rights Filter - is the mechanism used to block inherited rights from flowing down, which is the opposite of the concept described.

Inheritance describes how a trustee assignment made at a container level propagates downward through all subordinate objects and containers in the subtree, so a user granted rights to an OU automatically has those same rights to every object below it unless explicitly blocked by an Inherited Rights Filter.

Replication is the process of copying eDirectory partition data to multiple servers for availability and fault tolerance, unrelated to how rights propagate.

Partitioning is the division of the eDirectory tree into segments for distribution across servers, not a rights-flow mechanism.

Synchronization is the process of keeping replicated partition copies consistent across servers, not a description of rights propagation.

Distributed Administration is a strategy for delegating administrative authority across the organization, not the specific technical mechanism by which rights flow downward through the tree.