Statute of limitations

Daze filed his personal income tax for 2011 on May 4, 2012. He did not have any reasonable cause for delinquent tax filing. On top of that, he also inadvertently left out his lottery winning$20,000 from reporting on his tax return. His tax return without such lottery income shows$100,000 gross income.(1) The IRS initiated its audit on Dazes 2011 tax return on June 3, 2016. Does the IRS have authority to audit and possibly litigate Dazes tax return on the omission of lottery income?(2) Answer only one of the following two.i. If so, why?ii. If not, is there any circumstance under which the IRS would be authorized to conduct an audit?