NCA also could be:
National Cheerleaders Association
National Command Authority
National Committee on Accreditation
National Construction Authority
National Communications Authority
National Crime Agency - Not sure if this one is to do with committing crime, or stopping it.
Nothern College of Acupuncture
National College of Arts
New Christian Academy
National Capital Authority
Norwegian Church Aid
North Cancer Alliance - pretty sure this one is against cancer, rather than for it, though you never know.
Nippon Cargo Airlines
National Coffee Association
National Cybersecurity Authority