Given the following situations, identify whether each would require retrospective treatr prospective treatment:

A$)$ Switching from FIFO to Average Cost for inventory when it is practical to estimat

B$)$ Switching from a $3$ year useful life to a $5$ year useful life to depreciate a machine.

C$)$ Switching from percentage of completion to completed contract method for reve recognition of long$-$term projects.

$-$D$)$ Switching from double$-$declining balance to straight line for depreciation.

E$)$ Switching from expecting $3\%$ of Accounts Receivable to be uncollectible to $5\%.$

F$)$ Selling shares in another company that reduces our ownership stake from $30\%$ to