When a wallet service is used by an entity to hold its digital assets, which of the following statements is true?

a$.$ The wallet service should recognize the digital assets, regardless of the terms and conditions of the contractual arrangement.

b$.$ The reporting entity should continue to recognize the digital assets as long as it retains $$control$$ over the digital assets, per Topic $606$ factors.

c$.$ The reporting entity should recognize the digital assets, regardless of the terms and conditions of the contractual arrangement.

d$.$ The wallet service should recognize the digital assets if the digital assets are retained on a distributed ledger using blockchain technology.