Job/batch costing

Job costing is used when the business is doing specific jobs for customers, which is unlikely to be the case for any of these four. Batch costing is used when the goods are produced in batches (as opposed to individual units). The most likely ones to produce in batches of the four are (a) and (b). Why are you attempting questions for which you do not have an answer? You should be using a Revision Kit from one of the ACCA approved publishers - they have answers together with explanations :-)