A will be the answer because usually marking your exercise days will become a habit because lets say you would do a running exercise but you want to do it in a certain day well if you mark it on the calendar, it'll become a habit.
Answer:
Hi !
1. Autism and other developmental disorders =<u> Imply a deficit in a person’s imaginative activity and social ability</u>
2. Organic disorders =<u> Behavioral or psychological abnormalities that are associated with brain dysfunction</u>
3. Substance addiction disorder =<u> The frequent and dependent use of alcohol or drugs, which can negatively affect the central nervous system</u>
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Answer: the answer is actually D not C so yea its D