Final answer:
Mariah is providing taxpayer information in her taxpayer questionnaire for Form 1040, which includes income details, tax calculations, and information on deductions and credits.
Step-by-step explanation:
Mariah is providing c) Taxpayer information in her taxpayer questionnaire for Form 1040. Form 1040 is the standard Internal Revenue Service (IRS) form that individuals use to file their annual income tax returns. The form includes sections where taxpayers must provide their income, calculate their tax liability, and indicate any taxes already withheld from their income. It also allows for the documentation of deductions and credits to determine the amount of refund or additional tax owed.