According to the CCSSO model, which of the following might be called a dropout

A．Ability to read and write.
B．Ability to appreciate literature.
C．Lack of interest in literature.
D．Inability to read and write.

A．over one-tenth of American population have difficulty in using and writing skills in everyday situations
B．in North America nation-wide tests are given to test pupils' functional literacy
C．Canadians are generally at a higher level of functional literacy than Americans are
D．teaching of English reading and writing has turned out to be a failure in Canada and the U. S.