Which of these factors is least likely to change the natural rate of unemployment（）

A. An unexpected tightening of the money supply reduces aggregate demand.

B. Long-term demographic shifts result in fewer young adults in the labor force.

C. Labor market deregulation makes it easier for workers to change jobs.

全面发展身体，最大限度的挖掘和发挥人在体力、心理、智力等方面的潜力基础上，创造优异成绩为目的的运动过程是（）

A.大众体育

B.竞技体育

C.体育运动

D.学校体育