What is referential integrity action on delete/cascade?

• A. Cascade delete propagates deletion to dependent rows.
• B. Cascade delete propagates deletion to dependent rows; restrict/no action prohibits deletions that would break references; set null sets FKs to null.
• C. Set null is the only allowed action.
• D. Delete actions have no effect on dependent rows.

Answer: (B)

Referential integrity actions on delete describe what happens to related rows when a row in a parent table is deleted. The cascade option means the delete spreads to dependent rows, so nothing is left orphaned. The restrict or no action option prevents the delete if there are dependent rows, preserving the references. The set null option clears the foreign key in the dependent rows, leaving them intact but no longer linked to the deleted parent. Together, these describe the common ways a database can handle deletions to maintain consistency, which is why this option is the best match.