Q1: Sensor outputs destined for a digital computer system must first be processed by __________.

ANS:B - an ADC

Sensor output is analog signal it is in the level of Milli volt level and also for accesing money system in the form of digital signal so that it convert in the form of digital signal.
An analog-to-digital converter (abbreviated ADC, A/D or A to D) is a device that converts a continuous quantity to a discrete time digital representation. An ADC may also provide an isolated measurement. The reverse operation is performed by a digital-to-analog converter (DAC).

Typically, an ADC is an electronic device that converts an input analog voltage or current to a digital number proportional to the magnitude of the voltage or current.