In 2015, background investigation records from the Office of Personnel Management (OPM) were stolen. The theft included sensitive personnel files on over 21.5 million current, former, and prospective federal employees and contractors, including almost 5.6 million records with fingerprints. The incident led to a congressional investigation and the resignation of some OPM leaders. What was the main reason the breach occurred?

Group of answer choices

OPM personnel did not attend security awareness training.

An OPM contractor's laptop, which contained the files, was left in an unlocked vehicle.

OPM did not have an incident response plan in place.

OPM failed to prioritize its information security activities.