21.20. For the purposes of this Part, one corporation is associated with another in a taxation year if at any time in the year,(a) one of the corporations controlled, directly or indirectly in any manner whatever, the other;
(b) both of the corporations were controlled, directly or indirectly in any manner whatever, by the same person or group of persons;
(c) each of the corporations was controlled, directly or indirectly in any manner whatever, by a person and the person who so controlled one of the corporations was related to the person who so controlled the other, and either of those persons owned, in respect of each corporation, not less than 25% of the issued shares of any class, other than a specified class, of the capital stock thereof;
(d) one of the corporations was controlled, directly or indirectly in any manner whatever, by a person and that person was related to each member of a group of persons that so controlled the other corporation, and that person owned, in respect of the other corporation, not less than 25% of the issued shares of any class, other than a specified class, of the capital stock thereof; or
(e) each of the corporations was controlled, directly or indirectly in any manner whatever, by a related group and each of the members of one of the related groups was related to all of the members of the other related group, and one person who was a member of both related groups owned alone, or several persons who were members of both related groups owned together, in respect of each corporation, not less than 25% of the issued shares of any class, other than a specified class, of the capital stock thereof.