This is how you solve such problems.

Assume 這個說法對 and 美國人了解這點, then there is no need to let them know.

Assume 這個說法對 and 美國人不了解這點, then the bigger issue is why someone who doesn't know such simple fact got into a position that can 分派工作. Now you have identified a bigger problem. When you face multiple problems, you should always tackle the most serious one first.

The conclusion is obvious.