You Cannot Have an Invalid Entry in the Foreign Key

question 38

Multiple Choice

You cannot have an invalid entry in the foreign key column; at the same time, you cannot delete a vendor row as long as a product row references that vendor. This isknown as _____.

• A) batch updating
• B) referential integrity
• C) authentication
• D) cross joining  

---

Definitions:

Auxiliary Section

A supplementary part or segment of a machine or system, providing additional functionality or capacity.

Clockwise Rotation

A circular movement in the same direction as the hands move on a clock.

Gears And Shafts

Mechanical components that transmit rotational force; gears change the speed, torque, and direction of movement, while shafts support rotating parts and transfer motion.

Idler Gear

An Idler Gear is a gear positioned between two other gears to transmit motion from one to the other, often used to change the direction of rotation or to adjust the spacing between driving and driven gears.