Final answer:
The NIC was likely damaged by Electrostatic Discharge (ESD), which can occur when electrically charged objects come into contact and cause a sudden flow of electricity.
Step-by-step explanation:
The malfunction of the NIC after a spark jumped from your hand is most likely caused by Electrostatic Discharge (ESD). ESD occurs when there is a sudden flow of electricity between two electrically charged objects caused by contact.
This discharge can damage or destroy sensitive electronic components, such as a NIC, without proper grounding or protection.