Tango Corporation, a calendar year taxpayer, has been an S corporation for several years. Tango's business activities have become very profitable in recent years. On June 16, 2018, its sole shareholder desires to revoke the Selection. 

a. How does Tango revoke its Selection? When does the revocation take effect?

b. Assume Tango files a prospective revocation effective July 1, 2018. What tax returns are required of Tango for 2018? For 2019? When are these returns due?

c. If the corporation makes a new Selection after the revocation, when does it take effect?