Which of the following must be done to perfect an investment property by control?

To perfect a security interest in an investment property through control, having the issuer recognize the secured party is essential. This is because control provides the secured party with a means to enforce its security interest without the need for further action, creating a strong position in the ownership of the collateral.

In the context of investment property, which can include stocks, bonds, or interests in partnerships, control signifies that the secured party has the requisite rights to the collateral. When the issuer recognizes the secured party, it may involve steps such as providing written acknowledgment or making arrangements that clearly designate the secured party's status in relation to the investment property. This recognition is crucial as it solidifies the secured party's claim over the collateral, ensuring that the interest is valid against third parties, as required for perfection.

While other methods of perfection, such as filing with state authorities, may also apply generally to secured transactions, they are not the necessary elements for perfecting an investment property specifically through control. Possession of the investment doesn't align with the definition of control for investment property, as control is more about authority and acknowledgment by the issuer, not merely physical possession. Similarly, maintaining a bank account does not directly pertain to the perfection of an investment property like stocks or other securities.