The correct answer is 'Suboptimal placement of the wireless access point'. Placement of the wireless access point is critical to providing adequate signal strength throughout the office space. If the signal is weak in certain areas, it is likely due to physical obstructions or distance from the access point, indicating that it has not been ideally positioned. Walls, furniture, or metal objects can attenuate the signal, and areas that are too far away from the access point will naturally have weaker signals. The incorrect options are less likely given that the configuration is confirmed to be correct, and the reported issue specifically relates to certain areas, which points to a problem with physical placement rather than nationwide frequency interference or a faulty access point, unless there is concrete evidence that these factors are causing the problem.