William,a Cash-Basis Sole Proprietor,had the Following Receipts and Disbursements for 2013

William,a cash-basis sole proprietor,had the following receipts and disbursements for 2013: $\begin{array}{ll}\text { Gross receipts } & \$ 60,000 \\\text { Cost of sal es } & \$ 30,000\\\text { Other operating expenses }&\$6,000\\\text { Medical expenses }&\$600\end{array}$ For 2013,what amount should William report as net earnings from self-employment?

A) $30,000
B) $24,600
C) $24,000
D) $23,400
E) None of the above