Answer
See explanation
Work Step by Step
In part B we added three rows to add one major because of the three siblings, while in part C we added one row because for the 2nd student there is only one sibling.
If we didn't add three rows for the first case it would seem that the first student has only one sibling, to avoid this we added three rows.
Because the relation combines students, siblings, and majors in one table, adding a new major means repeating all data (student and sibling) for that student, which again demonstrates redundancy and the need for normalization.
