An engineer is designing a database for college course information and has created the following tables.

$\backslash$table$[[$Major ID$,$Major Name$],[10299313,$Physics,,$],[10234952,$Music,,$],[$Class ID$,$Class Name,Major ID$,],[58995855,$Astronomy,$10299313,],[58993213,$Fine Art,$10234952,]]$

In the above excerpt, the bolded Major ID field is an example of which of the following?

Source

Network

Relationship

Record