During its first year of trading, a trader collected $15000$ from credit customers. By the year-end, those customers still owed $600$. The amount paid to credit suppliers was $3000$, and at the end of the period $500$ was still due to them. No unsold goods remained in closing inventory. What was the gross profit for the period?
- A$10900
- B$11500
- C$12100
- D$12500