In Oracle SQL, date arithmetic can be performed directly, subtracting one date from another to get the number of days between them:

Option A:

SELECT (SYSDATE - DATE '2019-01-01') / 1 FROM DUAL; This query successfully calculates the difference between the current date and a specific date.

Option D:

SELECT SYSDATE - DATE '2019-01-01' - 1 FROM DUAL; This query subtracts a specific date from the current date and then subtracts 1 more day, which will execute successfully.

Option F:

SELECT SYSDATE - 1 - DATE '2019-01-01' FROM DUAL; Similar to D, this will successfully compute the date difference minus one day.

Options B, C, and E are incorrect because:

Option B and Option C: You cannot divide by a date or divide a date by a number.

Option E: You cannot subtract a date from a number.