单项选择题

当50≤X≤200时,则给变量Y赋值为1000的正确的if判定语句是()

A.if 50≤X≤200then y=1000
B.if x<=200andx>=50then y=1000
C.if x<=200orx>=50then y=1000
D.if x>=50,x<=200then y=1000