4. An ERD using Crow's Foot notation. The diagram should include: a) all entities, attributes, and relationships (including names) : b) primary keys (underlined) and foreign keys (italic) identified; c) cardinality and modality (optional / mandatory) symbols; and d) assumptions you have made, e.g., how you arrived at the cardinality and/or participation for those not mentioned or clear in the business description, etc