Answer:
Due to its effectiveness.
Explanation:
This drug still be successfully used in the treatment of this microbe because of its effectiveness on the microbes. All the microbes did not got resistance against the antimicrobial chemical and they are not full proof from the antibiotics so that's why the antimicrobial are used in the treatment of microbes. If all the microbes attain resistance against antimicrobial drug so it can't any affect on the microbes.
