A is the answer, the others have nothing to do with adjectives
I think is C because in the text it's the main idea.
According to the document of the Belmont report, there are three basic elements that the informed consent should contain; these elements are information, comprehension, and voluntariness. The three elements are needed in order to analyze an informed consent. Therefore, the correct answer is D: information, comprehension, and voluntariness best describe the principle of informed consent as described in the Belmont Report.
