Only relevant costs need to be considered in decision-making situations. Which of the following are relevant costs?

1 Project-specific costs 2 Avoidable future costs 3 Common costs 4 Unavoidable costs Select one: a. 2 and 4 only b. 1, 2, 3 and 4 c. 1, 2 and 3 only d. 1 and 2 only