McConnell's Bakeries Had the Following Balances on December 31,2012,before Any

McConnell's Bakeries had the following balances on December 31,2012,before any adjustment: Accounts Receivable = $100,000; Allowance for Uncollectible Accounts = $4,100 (credit) .McConnell's estimates uncollectible accounts based on an aging of accounts receivable as shown below:
$$\begin{array} { | c | c | c | } \hline \begin{array} { c } \text { Age Group } \\\text { (days past due) }\end{array} & \begin{array} { c } \text { Accounts } \\\text { Receivable }\end{array} & \begin{array} { c } \text { Estimated Percent } \\\text { Uncollectible }\end{array} \\\hline \text { Not yet due } & \$ 50,000 & 4 \% \\\hline 0 - 30 & \$ 20,000 & 8 \% \\\hline 31 - 60 & \$ 18,000 & 10 \% \\\hline \text { More than } 60 & \$ 12,000 & 40 \% \\\hline\end{array}$$
What amount of bad debt expense did McConnell's record in its December 31,2012,adjustment to the allowance account?

A) $10,200.
B) $12,800.
C) $15,300.
D) $6,100.