I'm given a comparative balance sheet that has the beginning and ending balances of the year. Allowances for doubtful accounts went from (2000) to...

I'm given a comparative balance sheet that has the beginning and ending balances of the year. Allowances for doubtful accounts went from (2000) to (6000). When compiling a form 1120 for federal tax purposes, how much do I put in for returns and allowances? (line 1b)