Which of the following source is most likely causing the issue in the case:
A user is reporting that he is undergoing periodic issues accessing the network, then you discover that the cable accessing the user’s PC to the switch is open to a fluorescent light fixture thanks to the investigation?

EMI is a form of interference that occurs when cables run too close to electrical devices. Crosstalk occurs when two cables interfere with each other. Attenuation happens when signal strength drops out. The option “Faulty cable” is also not true. It may be that a failed cable is the source of the problem. Nevertheless, the question asked for the most likely reason. Since the cable is working near fluorescent lights, the issue is more likely run with EMI.