The BGP ORF function can be used to control the maximum number of routes that...

Comprehensive and Detailed In-Depth Explanation:

TheOutbound Route Filtering (ORF)function in BGP allows a BGP speaker to inform its peer about the prefixes that it wants to receive, thereby reducing unnecessary route advertisements.

IP Prefix-List (D)is the correct answer because it is used to define the list of prefixes that are sent to the BGP peer during theORF capability negotiation.

Filter-policy (A)andRoute-policy (B)are used for controlling routing information locally or filtering incoming/outgoing routes but do not directly control the number of routes sent using ORF.

ACL (C)is primarily used for packet filtering and is not related to BGP route filtering.