The correct answer to the question is option 4, "Magic track pad." The Magic Trackpad is a device launched by Apple that allows users to operate a desktop computer using finger gestures, without the need for a traditional mouse. This device provides a similar experience to using a trackpad on a laptop, but it is designed for use with a desktop computer.

Option 1, "Mirror-image pad," is not the correct answer. This term does not accurately describe the device mentioned in the question.

Option 2, "Virtual pad," is also not the correct answer. While the Magic Trackpad could be considered a virtual pad in the sense that it is a touch-based input device, this is not the official name given to the device by Apple.

Option 3, "Fingertip track pad," is not the correct answer. While this term accurately describes the function of the Magic Trackpad, it is not the specific name given to the device by Apple.

Therefore, the correct answer is option 4, "Magic track pad," which is the official name of the touchpad device launched by Apple.