(a)[2]
Suggest two benefits of sending a signal digitally instead of by analogue transmission.
(b)[2]
State the purpose of the parallel-to-serial converter.
(c)[3]
In one telephone system, the sampling frequency is $8\,\text{kHz}$. During compact disc production, the sampling frequency is about $44\,\text{kHz}$. Suggest and explain why the sampling frequency is much greater for the compact disc.