Hi Dr Nasim, I am confused about Q10. What is the problem with the following query? SELECT job_id, po_date FROM pos WHERE po_date < '1990-01-03' GROUP BY job_id; A. The date is mentioned incorrectly B. po_date is not used in group by and is also not an aggregate function C. Order of groupby and where is wrong D. Group by always need to have a Having Statement The code provided in the question is runnable. Then, I changed it to "GROUP BY job_id, po_date" The code was also runnable and displayed the same result as without "po_date". Additionally, I changed '1990-01-01' to '1989-01-03' The code is still runnable and displays the correct result. Therefore, I am not sure why B is correct. Thank you for your assistance. Kind regards, Nate