Annual general meeting

Dear Sir, I would like to know how to calculate the date of the annual general meeting. What is the latest date that a public company incorporated on 1 May 2010, could hold it's 3rd AGM? A. 30 April 2014 B. 31 October 2013 C. 31 December 2013 D. 31 March 2014 The correct answer is C. According to my calculations, I got A. Because the 1 st AGM should be held within 18 months of the incorporation and the subsequent AGM should be held within 15 months. So total 48 months after the incorporation. Please guide me for the correct answer. Thanks.