The following data relate to the work in progress of stocks for SAS790 during November: Opening work in progress Nil Finished output to next process 7,000 litres Closing work in progress 1,200 litres Degree of completion – direct materials 100% Degree of completion – direct labour 50% The total labour cost is £3,800. The direct labour cost per litre of SAS790 of the equivalent finished production is: a. £0.45 b. £0.50 c. £0.60 d. £0.63