What type of objects can be operated by touching them on a touch screen terminal?

The correct answer is the type that is designed specifically for user interaction through touch. Pushbuttons on a touch screen terminal serve as interactive control elements that can initiate an action or trigger a response within a system when touched. These elements are visually represented on the screen and are responsive to user input, making them ideal for executing commands or navigating through software interfaces.

Pushbuttons are a core component in user interface design that simplifies interaction, allowing operators to easily control various functions just by tapping the relevant areas on the screen. Their functionality is integral to many systems, including programmable controllers, where quick and intuitive control over processes is essential.

While other options might involve elements in a system, they do not encapsulate the interactive nature of touch screens. Static objects would not respond to touch; output and tag refer to broader concepts that are not specifically actions initiated by touch input, but rather pertain to data representations and system functions.