Forwarding decisions: longest prefix match first, then administrative distance, then metric

Two different questions get mixed up in routing: which routes get into the routing table, and which of the installed routes a particular packet uses. Administrative distance (AD) and metric answer the first question. Longest prefix match answers the second. Keeping these separate is the key to getting CCNA forwarding questions right, because answer choices are often designed to tempt you into applying the wrong rule at the wrong stage. Think of it as two separate moments: building the table happens in the control plane as routes are learned, and choosing a route happens in the data plane for every packet.