$5)$ In reference to the determination of goodwill impairment, which of the following statements is correct?

A$)$ The goodwill impairment test under ASC $350-20-35$ is a three$-$step process.

B$)$ If the reporting unit's fair value exceeds its carrying value, goodwill is unimpaired.

C$)$ Under FASB $142,$ firms must first compare carrying values $($book values$)$ at the headquarter level.

D$)$ Firms can reverse previously recognized impairment losses.