Answer:
A. Protocols.
B. ARM.
C. Informed consent.
D. Drug interaction.
Step-by-step explanation:
A. Protocols: A study plan on which all clinical trials are based. This study plan should be designed carefully in order to protect the participant's health while addressing specific research questions.
B. ARM: Any of the treatment groups in a randomized trial. Thus, it is typically the different segments of study.
C. Informed consent: The process of learning the key facts about a clinical trial before deciding whether or not to participate.
D. Drug interaction: A modification of the effect of the drug when administered with another drug.