Digital readouts have tended to replace conventional dials and gauges

Digital readouts have tended to replace conventional dials and gauges in most machines. But the digital gauge has some draw-backs in some situations. It is difficult to tell from a digital readout whether the value is increasing on decreasing over time while the up or down movement of a pointer or analog gauge can be easily observed. An analog dial can be marked with red to alert the operator when a value is entering a danger zone whereas the numeric value in a digital meter has to be decoded and analyzed by a human operator. Its meaning cannot be read quickly in an instantaneous scanning. The use of the digital gauge is, therefore, recommended only in cases where ___________

Which of the following best completes the passage below?

A. warning of a sudden rise or fall in value is needed.

B. a precise numeric value is essential.

C. an operator must read and interpret several gauges within a few seconds.

D.several readings have to be taken over a period of time.

E. different operators use the same readings.