What does the writer think about the creation of new desert areas

A．Deserts can change into green and fertile areas.
B．Certain areas have always been desert.
C．Deserts were once the home of elephants and giraffes.
D．Deserts have been growing since the beginning of the worl

A．It is a natural development.
B．The problem is not very serious.
C．It is a very worrying problem.
D．The situation will improve in tim