Examine the description of the STUDENTS table: STD_ID NUMBER(4) COURSE_ID VARCHARD2(10) START_DATE DATE END_DATE DATE Which two aggregate functions are valid on the START_DATE column? (Choose two)

Explanation: Aggregate functions operate on a set of rows and return a single result. The two valid aggregate functions on the START_DATE column are: C. COUNT(start_date) - This function returns the number of rows where START_DATE is not null.

Option A is invalid because the SUM function is used to add numeric values and cannot be used with a DATE data type. Option B is invalid because the AVG function will not work with DATE, you can convert DATE to NUMERIC then it can be used, but without Casting it will not work Option D is invalid because the AVG function can only be used with a single column, and the argument passed in should be numeric.