Which of the Following Should Be Given Retrospective Treatment

Which of the following should be given retrospective treatment? $\begin{array}{l} &\text{ \underline{ Change in Estimated Lives of Depreciable Assets } } & \text{ \underline{ Change from Unacceptable Policy to Acceptable Policy } } \\A) & \text{ yes} & \text{ yes } \\B) & \text{ no } & \text{yes } \\C) & \text{ yes } & \text{ no } \\D) &\text{ no } & \text{ no } \\ \end{array}$