Which of the following is a correct statement? a. The INCLUDE NULLS keywords can be included in the argument for the COUNT function to include NULL values in the results. b. The NULL keyword can be included in the argument of the COUNT function to include NULL values in the results. c. An asterisk can be used as the argument for the COUNT function to include NULL values in the results. d. The ALL keyword can be included in the argument of the COUNT function to include NULL values in the results.