Final answer:
Informed consent requires several components, but one of the options listed is not necessary. The correct answer is d) Explanation that consent cannot be withdrawn after it's given.
Step-by-step explanation:
Informed consent requires several components, but one of the options listed is not necessary. The correct answer is d) Explanation that consent cannot be withdrawn after it's given. Informed consent involves providing participants with a description of the risks associated with the treatment, explaining the consequences of refusing treatment, and confirming that the patient is legally competent to give consent. However, it is important to note that consent can be withdrawn at any time in the process.