Question

Let \( S \) be the specification: "Instructors teach courses. Students register for courses. Courses are allocated classrooms. Instructors guide students." Which one of the following ER diagrams CORRECTLY represents \( S \)? \includegraphics[width=6.5cm]{21a.png}
\includegraphics[width=6.5cm]{21b.png}
\includegraphics[width=6.5cm]{21c.png}
\includegraphics[width=6.5cm]{21d.png}

• A. Diagram (i)
• B. Diagram (ii)
• C. Diagram (iii)
• D. Diagram (iv)

Hint:

When analyzing ER diagrams, ensure all relationships and entities in the specification are represented without introducing extraneous components.

Answer 1

The Correct Option is D

The correct ER diagram must fulfill the following requirements:
1. Instructors teach courses: The diagram should include a relationship named "Teaches" between "Instructor" and "Course."
2. Students register for courses: There must be an entity for "Student" and a relationship named "Registration" linking "Student" and "Course."
3. Courses are allocated classrooms: There should be a relationship named "Allocation" between "Course" and "Classroom."
4. Instructors guide students: The diagram must include a relationship named "Guides" between "Instructor" and "Student."
Analysis of the Options:
Option (i): Does not include the "Registration" relationship between "Student" and "Course." Incorrect.
Option (ii): Contains an additional entity "Projects," which is not part of the specification. Incorrect.
Option (iii): Does not include the relationship "Guides" between "Instructor" and "Student." Incorrect.
Option (iv): Includes all the required entities and relationships as per the specification. Correct. Final Answer: \[ \boxed{\text{Diagram (iv)}} \]