Final answer:
Anna's parents cannot claim her as a dependent if she is married and files a joint tax return with her spouse, except if the return is solely for a refund of withheld or estimated taxes. Social Security benefits and tax laws are complex and depend on individual circumstances and current law.
Step-by-step explanation:
The question pertains to whether parents can claim their married daughter, Anna, as a dependent if she files a joint tax return with her husband and had no tax due. According to IRS rules, a person cannot be claimed as a dependent if they are married and file a joint return with their spouse, unless that joint return is only filed to claim a refund of withheld or estimated taxes. Since Anna and her husband file jointly, Anna's parents cannot claim her as a dependent even if she had no tax due, unless the only purpose of the joint filing was to get a refund of taxes paid.
It's important to note that tax laws can be complex and are subject to change. Moreover, under certain circumstances, such as in the case of Social Security benefits for survivors like a widowed spouse, separate rules apply. For instance, the widow of a qualified worker will receive monthly benefits at age 65. Similarly, an aged dependent parent may get benefits under different circumstances.
The United States has a progressive tax system as shown by the 2014 tax brackets information for married filing jointly or qualifying widow/widower. However, this information should be updated to reflect current law and rates.