A network administrator has received complaints from employees about erratic wireless connectivity in an office space. After an initial survey, it is suspected that there may be interference affecting the wireless signal. Considering the office has recently installed several Bluetooth devices and microwave ovens in the break room adjacent to the affected area, which of the following sources is MOST likely causing the interference?
Florescent lighting fixtures installed above the office space
The microwave ovens operating in the break room
The construction materials used in the office walls
Cordless phones used by the employees within the affected area
The Bluetooth devices recently installed in the office