70.After a SAS program is submitted, the following is written to the SAS log:

  105    data WORK.JANUARY;

  106    set WORK.ALLYEAR(keep=Product Month Quantity Cost);

  107    if Month='JAN' then output WORK.JANUARY;

  108    Sales=Cost * Quantity;

  109    drop=Month Quantity Cost;

                      -----

                      22

  ERROR 22-322: Syntax error, expecting one of the following: !,

                !!, &, *, **, +, -,

  , <=, <>, =, >, >=,

                AND, EQ, GE, GT, IN, LE, LT, MAX, MIN, NE, NG, NL,

                NOTIN, OR, ^=, |, ||, ~=.

  110  run;

What data set option could be attached to WORK.JANUARY to replace the DROP statement that generated the error in the log?

     A. (drop Month  Quantity  Cost)

     B. (drop Month, Quantity, Cost)

     C. (drop=Month, Quantity, Cost)

     D. (drop=Month  Quantity  Cost)

这道题是不是应该选A呀，drop statement 不需要等号，而且也不应该有括号。D选项是应该用在SET 语句后面的。