What are some of the reasons a foreign key is important in databases

Question $27$ options:

a$)$

It uniquely identifies rows in a database

b$)$

While traditional databases don$$t use it$,$ it$$s used by cloud$-$databases to identify foreign data

c$)$

It helps join or link tables

d$)$

It helps transfer files to Azure web sites

e$)$

It is critical for viral marketing over the cloud