Which of the Following Is NOT an Element Identified by the AICPA

Which of the following is NOT an element identified by the AICPA as being necessary in order to use percentage-of-completion accounting?

A) The construction period can be reasonably estimated.
B) The buyer can be expected to satisfy obligations under the contract.
C) Dependable estimates can be made of the extent of progress toward completion.
D) Dependable estimates can be made of contract costs.