Since ______ Noam Chomsky and other generative linguists propose

Since ______ Noam Chomsky and other generative linguists proposed and developed a theory of universal grammar known as the principles-and-parameters theory.
A、early 1980s
B、early 1950s
C、late 1980s
D、late 1950s
【正确答案】：A
【题目解析】：Since early 1980s Noam Chomsky and other generative linguists proposed and developed a theory of universal grammar known as the principles-and-parameters theory.