IFRS 15 Revenue from Contracts with Customers states that, where performance obligations are satisfied overtime, entities should apply an appropriate method of measuring progress.Which TWO of the following are appropriate OUTPUT methods of measuring progress?(1)Total costs to date of the contract as a percentage of total contractrevenue(2)Physical milestones reached as a percentage of physical completion(3)Surveys of performance completed to date as a percentage of total contract revenue(4)Labour hours expended as a percentage of total expected labour hours