which of the following assertions is TRUE concerning conversion costs?

A. The conversion period often includes several operations, and it may be impossible to estimate conversion costs with any reliability in some cases.

B. When conversion costs are estimated to be over 80% complete, then the cost-benefit constraint requires us to use 100% as the estimate.

C. Conversion costs are impossibe to estimate with any relability.

D. direct labour costs are always included in conversion costs.

E. the conversion period(for conversion costs calculation)can only include one operation.