What characteristics of preferred stock require its classification as a liability on the balance sheet? Select one: a. Must include an unconditional obligation for the issuer to reacquire the shares at a specific date. b. Allows the stockholders to return the stock for payment at a specified price. c. Must include an unconditional obligation for the issuer to reacquire the shares at a specified or determinable date and at a specified price. d. Includes an unconditional obligation for the issuer to reacquire the shares at a specified or determinable date