I am not sure about my answers

7) Which of the following is an element of the database environment? a. Users b. Physical database C. Database administrators d. All of the above 8) A primary key can best be described as: a. A row within a table b. A unique attribute within a table C. A logical link between two tables d. All of the above 9) Cardinality can best be described as: a. The functional connection between two entities b. The degree of association between two entities Both A&B d. None of the above 10) Which of the following are duties of a database administrator? a. Database operation and maintenance b. Database planning c. Both A&B d. None of the above 11) Each economic event in an REA diagram is always linked to: a. At least two resource entities b. Another economic event C. Two extemal agents d. A support event 12) Which of the following associations would most likely describe the relationship between an internal agent and an economic event? a. 1.M b. 1.1 CM:M d. O:M 13) Which of the following tables would most likely have a composite key? a. Take Order b. Ship Goods C. Inventory-Ship Link d. Cash