Income less than 5 lakhs for itr

Hi,

I know that ITR filing is not mandatory  if the income is less than 5 lakhs. However for which of the below rows, we need to check in form 16, if it is less than 5 lakhs?

1)Salary as per provisions contained in sec.17(1)
2)Total Income (8-10) (Rounded off to nearest ten)
3)Gross total income (6 + 7) 
4)Income chargeable under the head 'Salaries'(3 - 5)