You are writing a query to find the number of ED visits that were discharged from non-ED units. The column dep. ADT_UNIT_TYPE_C column stores 1 if the unit was an ED Unit. Assume NULL values are non-ED units. Which of the following produces this number? A. SUM(CASE WHEN dep. ADT_UNIT_TYPE_C is NULL or dep. ADT_UNIT_TYPE_C <> 1 THEN 1 ELSE 0 END)
B. CASE WHEN dep. ADT_UNIT_TYPE_C is NULL or dep. ADT_UNIT_TYPE_C <> 1 THEN SUM (1) ELSE SUM (0) END
C. SUM(CASE WHEN dep. ADT_UNIT_TYPE_C is NULL or dep. ADT_UNIT_TYPE_C <> 1 THEN 'Non-ED Unit' ELSE NULL END)
D. CASE WHEN dep. ADT_UNIT_TYPE_C is NULL or dep. ADT_UNIT_TYPE_C <> 1 THEN SUM('non-ED Unit') ELSE SUM (NULL) END