Final answer:
The definition of "family member" according to 21 CFR 50 can include individuals with close associations to the subject who may not be related by blood, true to A) True.
Step-by-step explanation:
The question asks whether, according to 21 CFR 50, the definition of "family member" includes persons with close association with a subject who may not be related by blood. The answer to this is A) True. 21 CFR 50, which deals with the protection of human subjects in clinical trials, does not provide a specific definition of "family member." However, considering the ethics of human subject research, considerations about who is a family member can indeed extend beyond blood relations to include those with strong associative or emotional ties to the subject. It's important to remember that family structures vary widely, and ethical guidelines often need to accommodate for non-traditional family units when considering the well-being of the research participants.