Gemini Inc.'s optimal cash transfer amount, using the Baumol model, is $60,000. The firm's fixed cost per cash transfer of marketable securities to cash is $120, and the total cash needed for transactions annually is $960,000. On what opportunity cost of holding cash was this analysis based?

a. 9.2% b. 10.7% c. 6.4% d. 12.1% e. 9.6%