A major conceptual difference between throughput costing and variable costing is

1)under variable costing, direct labour and variable manufacturing overhead are charged to income as period expenses.

2)under throughput costing, direct labour and variable manufacturing overhead are deferred in inventory rather than charged to income as period expenses.

3)under throughput costing, direct labour and variable manufacturing overhead are charged to income as period expenses.

4) there are no conceptual differences between the two methods.