Which of the following refers to shares that a corporation can buy back from shareholders?

Redeemable shares refer specifically to shares that a corporation has the ability to buy back from its shareholders. This characteristic allows a company to repurchase these shares under the terms set forth when the shares were issued, which can be beneficial for both the corporation and the shareholders.

When a corporation issues redeemable shares, they typically set a specific price and conditions under which the shares can be repurchased. This can provide shareholders with a level of liquidity, knowing they can sell their shares back to the company under agreed-upon circumstances.

In contrast, ordinary shares, preferred shares, and common shares do not inherently carry the feature of being repurchased by the company. Ordinary and common shares generally represent ownership in the company with voting rights but lack a built-in mechanism for the company to buy them back. Preferred shares typically carry a higher claim on assets and dividends, but again, do not automatically include the option for redemption by the company. Thus, the unique attribute of redeemable shares distinguishes them as the correct answer, as they provide a defined buyback option for the issuing corporation.