Final answer:
The Certificate of Airworthiness application must be submitted within 15 days after the aircraft's condition is certified to comply with the aviation authority's regulations.
Step-by-step explanation:
The Certificate of Airworthiness (C of A) application form must be submitted within a specific timeframe after the aircraft's condition has been certified. The correct answer to the question is option b, which is 15 days. This is the period in which the application form must be filed after the certification to ensure the aircraft's operability and safety standards are in compliance with the aviation authority's regulations. The Certificate of Airworthiness application must be submitted within 15 days after the aircraft's condition is certified to comply with the aviation authority's regulations.