The command output in the exhibit shows that both AP radios are enabled, so a disabled radio is not supported by the evidence. The 5 GHz radio has relatively low channel utilization, while the 2.4 GHz radio reports channel utilization of approximately 90 percent. Such a high utilization value indicates that the air interface is heavily occupied by transmissions or interference. Huawei WLAN troubleshooting guidance identifies a busy air interface and a heavily loaded AP as possible causes of STA association failures because management and authentication frames may be delayed or lost when contention is severe. The displayed radio information alone does not prove that the affected STAs are in a blacklist or absent from a whitelist; those conditions require separate STA or VAP access-control information. Therefore, option A is the only choice directly supported by the command output. The correct troubleshooting interpretation is that excessive channel utilization on the radio can make the air interface busy and prevent some STAs from completing association successfully. The verified answer is A.