PL/SQL daily question: negative output

PL/SQL daily question: negative output question: Which options output a negative number? If you are sure that none of the following is correct, select E [SQL] www.2cto.com A DECLARE l_date2 DATE: = date '2017-12-20 '; l_date1 DATE: = l_date2-1; BEGIN Week (MONTHS_BETWEEN (l_date1, l_date2); END;/B DECLARE l_date1 DATE: = date '2017-12-20 '; l_date2 DATE; BEGIN DBMS_OUTPUT.put_line (MONTHS_BETWEEN (l_date1, l_date2); END;/c declare l_date1 DATE: = date '2017-12-20 '; l_date2 DATE: = l_date1; BEGIN DBMS_OUTPUT.put _ Line (MONTHS_BETWEEN (l_date1, l_date2); END;/d declare l_date1 DATE: = date '2017-12-20 '; l_date2 DATE: = l_date1-1; BEGIN DBMS_OUTPUT.put_line (MONTHS_BETWEEN (l_date1, l_date2); END;/knowledge point supplement -- MONTHS_BETWEEN usage instructions Oracle's MONTHS_BETWEEN date function returns the number of months between two dates, is the number of months between the first parameter date and the second parameter date. If the two parameters are equal, 0 is returned. If the first parameter is greater than the second parameter, positive is returned. If the first parameter is smaller than the second parameter, a negative number is returned. Obtain the number of months when getting the absolute value in the integer. Answer: ① A is correct ② B L_DATE2 is not assigned A value, so MONTHS_BETWEEN returns A null value. ③ If the two parameters are the same, return 0. ④ D results are the opposite of A, and return an integer