What characteristic best describes a KVM switch?

What characteristic best describes a KVM switch?

• a device that allows the use of one set of keyboard, mouse, and monitor to control multiple computers
• an input device often used to provide secure access to locations or devices by using voice, facial, or fingerprint recognition
• an input device allowing users to pay for a product by tapping their credit card or smartphone on another device
• an input device that reads barcodes affixed to most retail products