a. "Gross margin is the same as contribution margin.' Do you agree? Explain briefly. Type your answer here (2 marks) I b. Wang Ltd produces a single product which sells for $40 per unit. Variable costs are $20 per unit and fixed costs $80,000. Required: i. Calculate the break-even point in units and dollars. ii. Calculate the sales revenues required to obtain the operating income before tax of $60,000 iii. Calculate the net operating income after tax when sales revenue is $350,000, assuming the tax rate is 30%. iv. What is the breakeven level in dollars for Wang Ltd, assuming the selling price goes up by 20%, fixed costs increase by 10%, and variable costs decline by $5