Why are veterans' benefits regarded as an entitlement program?

Question $9$ options:

A$)$

Any individual who serves the nation by working for the federal government is entitled by law to receive veterans' benefits.

B$)$

Any individual who serves in the nation's armed forces is entitled by law to receive veterans' benefits.

C$)$

Like Social Security, veterans' benefits are available to all Americans, who are entitled to benefits simply because they are Americans and have benefitted from veterans' services.

D$)$

Any individual who serves the nation and provides public safety by working for a local police force or fire department is entitled by law to receive veterans' benefits.