can you please kindly help me with IAS 38 Intangible asset MCQ question?

Hi everyone,I am preparing f7 for this March session and I have one problem regarding the following IAS 38 question.if you guys could help me with this.I would really appreciate your effort.

Q.when a parent is evaluating the assets of the potential subsidiary,certain Intangible assets can be recognized separately from goodwill,even though they have not been recognized in the subsidiary’s own statement of financial position.

which of the following is an example of an intangible asset of the subsidiary which may be recognized separately from goodwill when preparing consolidated financial statements?

A.a new research project which the subsidiary has correctly expensed to profit or loss but the directors of the parent have reliably assessed to have a substantial fair value
B.a global advertising campaign which was concluded in the previous financial year and from which benefits are expected to flow in the future.
C.a contingent asset of the subsidiary from which the parent believes a flow of future economic benefits is possible
D.a customer list which the directors are unable to value reliably.

Correct Answer is A

i know the D cant be the answer because from what i have read from the book that customer list is indistinguishable from the goodwill but isnt it a purchased intangible asset ? and for A i thought that would be a research cost as they have already expensed it so why A is actually a correct and C is IAS 37 so it cant be IAS 38

i thought the answer would be B

Thanks in advance and i am looking forward for the explanation to this question from you.