The reason why so many ad claims fall into the category of false information is ______ par

The reason why so many ad claims fall into the category of false information is ______ parity products, those in which most of the brands available are nearly identical.

A．due to they are applying to

B．that they are applied to

C．because they are applied to

D．because they are applying to

请帮忙给出正确答案和分析，谢谢！