For which months can Martha be treated as having earned income if she was a full-time student from January 1 to June 30?

Martha can be treated as having earned income from January through June because this period corresponds to her status as a full-time student. The IRS allows students to qualify for certain tax benefits and credits, such as the Earned Income Tax Credit, based on the months they are considered to have earned income.

For the purpose of the tax laws, typically, the months in which a full-time student is enrolled in educational programs can be treated as months of earned income for specific tax calculations. In Martha's case, since she was a full-time student for the entire duration from January 1 to June 30, both the income she earned during that time and her status as a student apply through these months. Once July begins, and she is no longer a full-time student, her eligibility for this particular status would not apply for the remaining months of the year.

Therefore, the correct timeframe for which Martha is treated as having earned income is from January through June.