请教一道题目：The Excel workbook QTR1.XLS contains the following three worksheets:JAN FEB MAR.
Which statement correctly assigns a library reference to the Excel workbook?
A.libname qtrdata 'qtr1.xls';
B.libname 'qtr1.xls'sheets=3;
C.libname jan feb mar 'qtr1.xls';
D.libname mydata 'qtr1.xls' WORK.sheets=(jan,feb,mar);