The scenario describes a discrepancy between what the Access Point (AP) can receive and what the portable analyzer can capture at the same physical location (near the AP). The low retry rate (<2%) confirms that the AP is successfully receiving frames from the client station (STA). However, the analyzer at that location cannot see these frames. This indicates that the AP has a better receive sensitivity than the analyzer. The client's signal is strong enough for the AP's high-quality receiver to decode but too weak for the analyzer's less sensitive receiver at that distance. When the analyzer was near the client, the signal strength was sufficient for it to capture the frames.

A. This is incorrect because the low retry rate proves the AP is not blinded and is successfully receiving the client's packets.

B. A mismatch in spatial stream support would likely prevent the analyzer from decoding frames regardless of its proximity to the STA, which contradicts the initial successful capture.

C. This is contradicted by the evidence. The low retry rate explicitly indicates that the AP can hear the client's traffic successfully.

1. CWNP, LLC. (2021). CWAP-404 Certified Wireless Analysis Professional Official Study Guide.

Chapter 11: WLAN Frame Analysis, Section: Capture Hardware. This chapter discusses the hardware used for packet capture, noting that the capabilities of capture adapters (like those in a portable analyzer) can vary significantly and may not match the performance of an enterprise-grade AP. It states, "The quality of the radio and antenna in the capture device will affect its ability to hear frames... An enterprise-grade AP will almost always have a better receive sensitivity than a USB NIC." This directly supports the conclusion that the analyzer's hardware is less capable than the AP's.

2. Cisco. (2019). Enterprise Mobility 8.5 Design Guide.

Chapter 3: RF Design Considerations, Section: Receiver Sensitivity. This guide details the importance of receiver sensitivity for APs in establishing reliable communication links. It explains, "Receiver sensitivity is the measure of the ability of a receiver to receive weak signals." Enterprise APs are designed with high receiver sensitivity to maintain connections with clients at the cell edge. This establishes that APs are engineered to receive weaker signals than typical client-grade or portable analysis hardware.

3. Sikora, A., & Groza, V. Z. (2005). A survey of 802.11 network performance and vulnerability analysis tools. In IEEE Instrumentation and Measurement Technology Conference Proceedings (Vol. 2, pp. 1539-1544). IEEE.

DOI: 10.1109/IMTC.2005.1604421

Section III: WLAN Analysis Tools. This academic survey discusses the limitations of various WLAN analysis tools. It implicitly supports the answer by highlighting that the physical layer capabilities (PHY), including the sensitivity of the radio chipset in the analysis tool, are a critical factor in the accuracy and completeness of a packet capture. A discrepancy between the analyzer's capabilities and the network hardware's capabilities can lead to incomplete data, as seen in the question's scenario.