a-the value of preferred stock can potentially rise when long-term bond yields decline
b-because trading volume of preffered stock is lower than common stock, preffered stock prices are less volatile than common stock
c-the yield differencial between preffered stock and bond is smaller than would be expected on the basis of risk differential
d-preferred stockholders receive preferencial treatment over lower-class, common stockholders when the corporation earns sufficient profit to pay creditors and shareholders.