GHI Industries operates four divisions: North, South, East, and West. The following financial data is provided for the year ended 31 December 2024:

Item	North ($)	South ($)	East ($)	West ($)	Total ($)
Sales revenue	500,000	400,000	300,000	200,000	1,400,000
Variable costs	250,000	200,000	150,000	100,000	700,000
Fixed costs	100,000	80,000	60,000	40,000	280,000

Required: a. Prepare a responsibility income statement for each division. b. Calculate the contribution margin and segment margin for each division. c. Evaluate the performance of each division based on the segment margin. d. Discuss the benefits and challenges of decentralization in an organization.