Rule: An individual may file an amended tax return (Form 1040X) within three (3) years of the date the original return was filed or within two (2) years of the date the tax was paid, whichever is later. An original return filed early is considered filed on the due date of the return. Choice "C" is correct. In this question, the return was filed early (April 1), so the return is considered filed as of the due date, on April 15. There is no information on when the tax was paid, but it can be reasonably assumed that the tax was properly paid on April 1 with the return. So the latter of the two dates is three years. The question that arises is "three years from when," and here the question falls somewhat short. Three of the answers to this question are worded in terms of "the" calendar year. These answers have to mean the prior calendar year. Three years from April 15 (when the return was considered to be filed) would be three years, three months, and 15 days from the end of the prior calendar year.Choice "b" is incorrect. The date is not four months and 15 days after the end of the (prior) calendar year. This answer ignores the three years. It appears to be trying to trick candidates into thinking that April is four months. However, that would mean that the last day that an amended return could be filed was the date of the filing of the original return.
Choice "d" is incorrect. The date is not ten months and 15 days after the end of the (prior) calendar year.
Choice "a" is incorrect. The date is not three years after the (original) return was filed. This answer looks good at first glance, but note that the return was actually filed on April 1. The Rule above considers an original return filed early to be filed on the due date of the return. However, the answer says "after the return was filed" and not "after the return was considered to be filed."