The correct answer is D. Touch.
A touch screen is a type of input device that allows a user to interact with a computer or other electronic device by touching the screen with their fingers. Touch screens are becoming increasingly common on mobile devices, such as smartphones and tablets, as well as on laptops and desktop computers.
A joystick is an input device that is typically used for controlling video games. It consists of a stick that can be moved in any direction, and buttons that can be pressed. Joysticks are also used for controlling some types of industrial machinery.
A light pen is a pointing device that is used to interact with a computer. It consists of a pen-shaped device that emits a light beam. When the light beam is pointed at a specific location on the screen, the computer can detect the location and perform the corresponding action. Light pens are no longer commonly used, as they have been replaced by other pointing devices, such as the mouse.
A mouse is a pointing device that is used to control the cursor on a computer screen. It consists of a small, handheld device with two or more buttons and a scroll wheel. The mouse is moved across a flat surface, such as a mouse pad, to move the cursor on the screen. The buttons are used to select items and perform actions, and the scroll wheel is used to scroll up and down on a page.
The answer is D. Touch because it is the only option that does not require the use of a keyboard.