How frequently must research facilities be inspected according to Animal Welfare Act regulations?

Research facilities must be inspected at least once a year according to Animal Welfare Act regulations. This requirement is established to ensure that facilities comply with laws regarding the care and use of animals in research. Annual inspections help regulatory authorities assess the living conditions of animals, maintenance of facilities, and adherence to protocols aiming to minimize suffering and ensure proper care. The annual frequency strikes a balance; it is frequent enough to catch any emerging issues, yet spaced enough for facilities to implement any necessary improvements identified during inspections.

The other options suggest either more or less frequent inspections than what the regulations stipulate, which would not provide the necessary oversight required to maintain humane standards in animal research.