B. Microphone helps Carol to use the speech recognition software.
Explanation:
A microphone is a hardware device which converts the sound waves in the air into electronic signals. The electrical signals are transferred to a recording medium. Four main types of microphones are as follows:
i) Cardioid
ii) Super cardioid
iii) Omni
iv) Figure 8
Handheld microphone can be used better with the home theater or a karaoke machine. The speech recognition software can be used with the help of microphone. Cabling problem can be avoided with the use of microphone, thus cable trip hazard can also be avoided.
