Sonic promotes Claudia S. San Pedro to president and Corey R. Horsch to chief financial officer   Treasurer elected to chief financial officer and hotel veteran elected to board of directors OKLAHOMA CITY, 2018-Feb-06 — /EPR Retail News/ — Sonic Corp. (NASDAQ: SONC), the nation's largest chain of drive-in restaurants, today (Feb 2, 2018) announced promotions of Claudia S. San Pedro to…