Which of the following can best sum up the passage

A．Musical instruments developed through the years will sooner or later be replaced by computers.
B．Music cannot be passed on to future generations unless it is recorded.
C．Folk songs cannot be spread far unless they are printed on music sheets.
D．The development of music culture is highly dependent on its material aspect.

A．it has a great effect on the music-culture as more and more people are able to read it
B．it tends to standardize folk songs when it is used by folk musi clans
C．it is tile printed version of standardized folk music
D．it encourages people to popularize printed versions of songs