Final answer:
Margie, who is 15, is most commonly claimed as a dependent by her parents on their tax return, which is answer option B.
Step-by-step explanation:
The question you've asked relates to who can claim a dependent on a tax return. If Margie is 15 years old, she is most likely claimed as a dependent on a tax return by her parents or legal guardians. It is less likely for a sibling to claim her unless they provide for more than half of her support and meet certain IRS qualifications.
A friend generally cannot claim someone as a dependent unless they meet stringent qualifications set by the IRS, which includes the dependent living with them all year as a member of the household and providing over half of the dependent's support.
In this case, the most common and correct answer is B) by her parents on their tax return. Margie's parents would likely provide the majority of her financial support, and since she is under the age of 19 (or under 24 if a full-time student), they generally have the right to claim her as a dependent on their tax return.