Answer:
Annually
Step-by-step explanation:
A mechanic must examine all vehicles used to carry children on a yearly basis to verify appropriate functioning condition. The mechanic's documentation must be kept in the car. A vehicle used for the regular transportation of children must be properly examined by a mechanic at least once a year, not considering routine maintenance such as oil changes. This is done not just for safety reasons, but also to provide maximum seating and seat belt capacity.