Concerning Application of the Lower of Cost or Market Method

Concerning application of the lower of cost or market method under either the LIFO or retail inventory method, which one of the following statements is true regarding the constraints on market value?

A) The upper constraint is estimated selling price less costs of completion and disposal.
B) The lower constraint is net realizable value less costs of completion and disposal.
C) The lower constraint is estimated selling price less a normal profit margin.
D) The upper constraint is estimated selling price less costs of completion and disposal and a normal profit margin.