Answer: A.
Explanation:
Proteins are the things that determine what functions will play out. They are the reason we are able to digest foods, transfer oxygen throughout the body. Proteins MAKE these functions happen. Without proteins, we wouldn't be able to do anything
The 3 domains are bacteria, archaea, and eukarya. The domain bacteria consists of the kingdom 'bacteria'. The domain archaea consists of the kingdom 'archaea.' The domain eukarya consists of the kingdoms 'plantae', 'animalia', 'fungi', and 'protista.'