提建议：We should / shouldn't... — 英语选择题
题目
学校要开展“Keep It Green”环保周活动。Ben 发现有些同学洗手后不关水龙头，浪费了水。下面哪一条是 Ben 应该提的正确且合理的建议？
A. We should leave the water running after washing hands.
B. We should turn off the tap after washing hands.
C. We shouldn't wash our hands every day.
D. We shouldn't save water at school.