Which method changes the forwarding decision that a router makes first changing the routing table or influencing the IP data plane?

Policy-based routing (PBR) inspects packets at the data plane and applies defined rules (policies) to determine the next-hop for specific traffic, overriding the traditional destination-based lookup in the routing table. This allows for flexible traffic engineering based on criteria beyond just the destination IP address, such as source IP, port, or protocol.

Nonbroadcast multi-access (NBMA) is a network type where multiple devices are connected but broadcasts are not natively supported, relevant to technologies like Frame Relay, not a method for changing forwarding decisions.

Packet switching is a fundamental method of grouping data into packets for transmission across a network, which is the underlying mechanism for all IP forwarding, not a specific method to change forwarding decisions.

The Forwarding Information Base (FIB) is the optimized data structure derived from the routing table used by a router to make forwarding decisions efficiently, but it is the result of routing decisions, not a method to change them independently of policy.