When conducting a Layer 2 site survey, it is recommended to match the survey to the worst client available. This ensures that the wireless network is designed to provide adequate coverage and performance even for clients with the poorest RF capabilities, thereby providing a consistent user experience for all devices. The worst client typically has fewer antennas, lower receiver sensitivity, and less sophisticated chipsets. By designing to its limitations, the engineer guarantees that every device in the environment meets the minimum performance threshold. Using the best client (Option A) or an average client (Option C) would result in coverage gaps for less capable devices. A phone client (Option B) may have unique characteristics but is not a universally applicable standard for general survey purposes. Reference: WLSD Study Guide — Site Survey Methodology, Client Selection for Survey, Layer 2 Pre-Deployment Survey.