In this Part-
"business" includes-
(a) a profession or trade, and
(b) any other activity carried on for fee, gain or reward, and
(c) the activity of employing one or more persons who perform duties in connection with another business, and
(d) the carrying on of a trust (including a dormant trust), and
(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.