Final answer:
The XLR connector is the three-pronged cord commonly used for sound signal transfer, providing a balanced audio signal and minimizing noise and interference.
Step-by-step explanation:
The three-pronged cord mostly used for sound signal transfer is c. XLR. An XLR connector is commonly used in professional audio and video electronics cabling applications, especially for microphones and other sound equipment. It provides a balanced audio signal that helps to minimize noise and interference. The XLR connector is designed with three pins - two for the signal and one for grounding. This makes it an industry standard for high-quality audio transmission.