16. The Scottish Ministers may withhold or recover the whole or any part of any payment of less favoured area support payable or paid to an applicant in any of the following circumstances:–
(a)where the applicant fails to comply with the terms of an undertaking given by that applicant pursuant to regulation 4(1)(a) from which the applicant has not been released under regulation 4(3);
(b)where the applicant, or an employee or agent of the applicant intentionally obstructs an authorised person in exercise of the powers under regulation 14, or fails without reasonable excuse to comply with a requirement or request made by an authorised person under regulation 14 or 15;
(c)where, in the opinion of the Scottish Ministers, the applicant has failed to act in accordance with usual good farming practices on or in relation to eligible land;
(d)where, in the opinion of the Scottish Ministers, the applicant has failed to comply with the environmental controls set out in Schedule 3 on or in relation to eligible land.