单项选择题
Which command generates a BERT test pattern of alternating ones and zeros on T1 number 1 for one minute?()
A. t1 1 bert pattern alt01 interval 1
B. t1 1 bert pattern alt01 interval 60
C. t1 1 bert pattern alt-0-1 interval 1
D. t1 1 bert pattern alt-0-1 interval 60