Refer to the exhibit.

The root bridge election is based on the lowest bridge ID. The bridge ID includes priority and MAC address, with priority compared first. If priority values are not provided or are equal, the lowest MAC address becomes the tie-breaker. In the HQ LAN exhibit, Switch 3 has the lowest bridge ID value after the election criteria are applied, so Switch 3 becomes the root bridge. Cisco CCNA 200-301 v1.1 Network Access tests this because STP root placement determines which switch becomes the logical center of the Layer 2 topology. Once the root is selected, all nonroot switches calculate their root ports and designated ports based on path cost and tie-breakers. The physical drawing position of a switch is irrelevant. The root is chosen by numerical bridge ID comparison. The correct answer is C.