4 Suppose the following were the gross profit margins for Green Mountain Coffee Roasters (GMCR) from 2011 through 2013. 2011: 34.13% 2012: 32.89% 2013: 37.16% What could be an explanation of the fluctuations in gross profit margins for GMCR from 2011 through 2013? ( select any One ) A.0 Selling & Operating expenses went from 13.15% to 12.48% to 12.86% from 2011 to 2013. B.0 Labor and Overhead costs were lower as a percentage of Sales in 2012. C.0 An increase in manufacturing capacity at the beginning of 2012 caused overhead to increase but allowed for greater efficiency and significant sales growth later