includes:

(a) a profession or trade;

(b) any other activity carried on for fee, gain or reward;

(c) the activity of employing 1 or more persons who perform duties in connection with another business;

(d) the carrying on of a trust (including a dormant trust);

(e) the activity of holding any money or property used for or in connection with another business, whether carried on by 1 person or 2 or more persons together.