1. The answer would be B. be listed alphabetically by last name.
2. The answer is C. The time and date you read source materials is not necessary.
3. I believe the answer is B. You would not want to combine opinions and general statements, You would keep them separate.
4. The answer is B. periods.
5. The answer is A. Authors in scholarly journals are generally specialists in their field.
6. The answer is A. comma.
Hope this helps!