Explanation:

• Option A (Correct): Direct investment in cryptocurrencies involves owning the digital assets outright, which necessitates the use of a cryptocurrency wallet. This wallet stores the public and private keys required to access and manage the assets on a blockchain.

• Option B (Incorrect): ETFs that replicate digital asset returns typically use derivatives or other financial instruments rather than holding the actual cryptocurrencies. As a result, investors do not need a cryptocurrency wallet.

• Option C (Incorrect): Cryptocurrency trusts allow investors to trade shares representing pooled holdings of a cryptocurrency. Since the trust manages the underlying assets, individual investors do not require a wallet or encryption keys.