4. Which of the following is true of the earned income credit? a. It cannot exceed the amount of the tax liability. b. It is available to U.S. residents with no Social Security number. c. It is available only if the taxpayer has qualifying children. d. In some cases, it must be calculated on earned income and adjusted gross income. Which of the following is true regarding the child and dependent care credit? a. It is available only to single parents. b. It is allowed only for taxpayers earning less than $43,000. c. It is available for the care of a spouse incapable of self-care. _ d. It applies only to children under age 15