In some parts of China, it is a common

In some parts of China, it is a common _____ that it is the wife who is responsible for the meals a
A. sense B. practice C. knowledge D. idea
解释一下!
and clothes-washing for the whole family.
答案给的是B我查了一下，有下面的解释，你们看对吗？总觉的很别扭，硬往答案上靠的感觉！
习惯,常规,惯例[C][U]
The old practice still prevails in the countryside.
旧习俗在乡间仍然流行。

根据你查的的解释,答案没问题呀
practice 在这里就是习俗的意思,
that 往后为practice的同位语