Answer: B. Digital input
Answer analysis:
DigitalInput refers to an input port that uses a digital signal as an input signal to input digital quantities, such as switching status, counter status, etc.
In the digital input process, there are only two possible values of the input signal, either high or low, which are usually processed by digital logic circuitry.
Unlike analog inputs, digital inputs require analog-to-digital conversion and transmit digital signals to the input port. Digital inputs are often used to connect and interact with digital circuits or digital signal processing devices.