Answer:
The correct answer is d.In an E-R model, the three types of maximum cardinality are 1:1, 1:N, and N:M.
Explanation:
An entity relationship diagram is a diagram that illustrates how "entities" relate to each other. ER diagrams of a system are often used to design or refine relational databases in the areas of software engineering, business information systems, education, and research. Also known as the ERD model or ER model, they use a set of defining symbols such as rectangles, rhombuses, ovals, and links to express the cohesion of entities, relationships, and their properties. They are a reflection of the grammatical structure and the use of entities as nouns and relationships as verbs.
