Outstanding stock of the Toell Corporation included 40,000 shares of $5 par common stock and 20,000 shares of 6%, $10 par non-cumulative preferred stock. In 2006, Toell declared and paid dividends of $8,000. In 2007, Toell declared and paid dividends of $24,000. How much of the 2007 dividend was distributed to preferred shareholders:
a) $12,000
b) $28,000
c) $16,000
d) $24,000