Buster Ltd Had Purchased Goodwill to the Value of $100

Buster Ltd had purchased goodwill to the value of $100 000 recorded in its consolidated financial statements.The goodwill has been determined to have an indefinite useful life.However,one year later Buster Ltd's cash generating units has been determined to have incurred an impairment loss of $13 000.What is the appropriate action for Buster limited to comply with AASB 138 Intangible Assets and AASB 136 Impairment of Assets?

A) Write-off goodwill in its entirety as goodwill no longer exists.
B) Recognise impairment loss of $13 000 and credit goodwill.
C) Amortise goodwill for 20 years using straight-line method.
D) Recognise impairment loss of $13 000 and credit equity.