Final answer:
The condition that is NOT a test for qualifying child criteria is that the dependent's gross income should be less than a set amount for the year.
Step-by-step explanation:
The qualifying criteria for a qualifying child do not include the condition that the dependent's gross income should be less than a set amount for the year; that condition applies to qualifying relatives instead. Thus, the correct answer is a. If the dependent's gross income is less than a set amount for the year ($4,300 in 2020). The other options, b. Whether the qualifying child does not provide more than one-half of his or her own support during the year, c. Whether the dependent has lived with the taxpayer for more than half the year, and d. If the qualifying child dependent is a descendant of the taxpayer, the taxpayer's sibling, or a descendant of the taxpayer's sibling, are all part of the tests that must be satisfied for a qualifying child.