16. A claimant is by virtue of this regulation released from the undertaking referred to in regulation 5–
(a)at the moment he first receives a retirement pension;
(b)if he is prevented from continuing to discharge that undertaking by reason of any material circumstances beyondhis control; or
(c)if he ceases farming and at least three hectares of his eligible land, or the eligible land used by him for the grazing of animals, continues to be used for agricultural purposes.