Mrs. Calvin cannot claim her son Drew as a dependent because he earned $5,000. What filing status must she use?

Mrs. Calvin's inability to claim her son Drew as a dependent due to his earned income suggests that he does not meet the criteria for a qualifying child. To be considered a qualifying child, he must have specific characteristics, including being under a certain age and having income below a certain threshold. Since Drew has earned $5,000, which exceeds the income limit for a qualifying child, Mrs. Calvin cannot claim him as a dependent.

Given this situation, her filing status must conform to her circumstances outside of dependency claims. If she is unmarried and does not qualify for other statuses like Head of Household or Qualifying Surviving Spouse, her only option is to file as Single. This status applies to individuals who are not married, do not have qualifying dependents, and do not qualify for any other specific filing status. It accurately reflects her situation based on the information provided.

If Mrs. Calvin were married, her options might differ, but with no mention of her marital status and the requirement to select based on her current situation regarding her son, Single is indeed the appropriate filing status for her.