Final answer:
Glutathione S-transferases (GSTs) are the enzymes that transfer water-soluble groups in phase II of drug metabolism, and the correct answer is 'c) GST'.
Step-by-step explanation:
The enzymes that transfer water-soluble groups in phase II of drug metabolism are glutathione S-transferases (GSTs). These enzymes play a crucial role in the biotransformation processes, facilitating the conjugation of drugs or their metabolites with glutathione, which usually leads to the formation of more water-soluble compounds that can be easily excreted from the body. This particular function is distinct from that of the Cytochrome P450 enzymes (CYPs), which are involved in phase I of drug metabolism, primarily responsible for oxidation and reduction reactions. Therefore, the correct answer to the question is 'c) GST'.