The Rock Corporation acquired all of the outstanding common stock of the Flynn Corporation in exchange for $300 million cash. Smithson assumed all of Rider's long-term liabilities, which have a fair value of $150 million at the date of acquisition. The fair values of all identifiable assets of Rider are as follows: receivables of $75 million, supplies of $90 million, property, plant, and equipment of $135 million, and trademarks of $120 million. What is the cost of goodwill resulting from the acquisition? $45 million $30 million $75 million O $60 million