题目

Pop music is the name for different forms of popular, commercial（商业） music．It had its beginning in the USA and spread throughout the whole world during the 1950s and 1960s．It is widely liked by the young people．The best known early form of pop music was “rock’ n’ roll”; another was “blues”． A more recent development is “folk-rock”．Pop music has taken the place of native music in many parts of the world; it has caused the number of people for jazz to become much smaller than it was in the 1950s and earlier, and it has now begun to rule musical stage productions The authorities declared that because of the war petrol was _____ and had to be rationed (定量供应).    A. inadequate    B. rare    C. lacked    D. scarce