of all 在这里怎么理解啊?

问题描述:

of all 在这里怎么理解啊?
of all the diseases associated with somking ,addiction is perhaps __that receives the least attention.
A one B the one C none D soneting

B.the one
of all 表示部分与整体的关系,"所有的.中的..."
句意:在所有和吸烟有关的疾病中,也许人们最容易忽略的就是吸烟上瘾