According to Ian Redpath and Robert Feenan, with all other factors being equal, witch of the following is most likely to be clasified as a trade or business. 

a) business abc showed a profit in 2 out of 3 years 

b) business bcd showed a profit in 3 out of 5 years 

c) business cde showed a profit in 4 out of 7 years 

d) def showed a profit is 5 out of 8 years