Which test must be performed without using hands?

For the situation described, the attachment test is the correct choice as it is typically performed without the use of hands. This test may involve assessing the response or connection of attachments using the remote control system, ensuring that the equipment or machinery correctly recognizes and interacts with different attachments.

Conducting the attachment test without hands allows the operator to verify the functionality while adhering to safety protocols, as manual handling could introduce risk or compromise the integrity of the testing process. In this way, the operator can ensure that the system's remote operational functions work correctly without the interference or distraction of physical manipulation.

In contrast, the other tests may inherently require personal interaction or manual input to complete effectively.