How many times may a candidate retake the ADI Part 1 written exam if they fail, and how many attempts are allowed for each practical part (2 and 3)?

1. Only one attempt is allowed for the theory exam and each practical part
2. Unlimited attempts for every part of the qualification
3. A maximum of three attempts for the theory exam; unlimited attempts for each practical part
4. Unlimited retakes for the theory exam; a maximum of three attempts for each practical part