If Gymshark changes its corporate objective from profit maximisation to sales maximisation (output maximisation) subject to making at least normal profit, it will operate at an output level where:
price equals marginal cost
average revenue is equal to average cost
marginal revenue is equal to zero
marginal cost is minimised
16 exam-style questions on Edexcel A A Level Economics 3.2.1 Business objectives. Each one has a worked solution and a mark scheme showing where the marks go.