请选择CBA(t3H.x7f7|/W;N/`7m;m(U3k9~'I When the______ is on（亮）, drivers must stop.(D+S5z.R.`-['q/{,G5h
A. yellow light(D+S5z.R.`-['q/{,G5h
B. red light(D+S5z.R.`-['q/{,G5h
C. green light(D+S5z.R.`-['q/{,G5h