Answer: C
Funds reflect different economic relations with stocks and bonds. Stock reflects a kind of ownership relationship, which is a kind of ownership certificate. After investors buy shares, they become shareholders of the company. Bonds reflect the relationship between creditor's rights and debts, which is a kind of creditor's rights certificate. Investors become creditors of the company after buying bonds. The fund reflects a trust relationship, which is a beneficiary certificate. Investors will become the beneficiaries of the fund when they buy fund shares.