n general, the best way for replacement of lamp is _____.A.after the point is reached at w

n general, the best way for replacement of lamp is _____.

A.after the point is reached at which the failures begin to increase rapidly

B.before the point is reached at which the failures begin to increase rapidly

C.before the point is reached at which the failures begin to increase slowly

D.after the point is reached at which the failures begin to increase slowly

请帮忙给出正确答案和分析，谢谢！