Answer: September 1, 2017
Explanation: The statute of limitation could be explained as a window period within which a civil violation or case may be filed by a plaintiff. Once this window period expires, the defendant may raise a claim against such case with respect that statute of limitation has been violated. In the scenario described above, the offense could be regarded as a professional malpractice with a statute of limitation of two years after the discovery of the incident which in this case is October 1, 2015, hence the statute of limitation of the sale will run out 2 years after October 1, 2015 which is September 1, 2017.