Jackson (30) is married and lived apart from his wife, Carol (28), the entire year. They have no decree of divorce of separate maintenance. Carol does not want to file a joint return with Jackson. Bill (6), their son, lived with Carol the entire year. Carol has waived her right to Bill's exemption for 2021 by signing Form 8332. Jackson and Carol both provided 50% of Bill's support. Jackson's wages were $37,000; Carol's were $39,000; Bill's gross income was $0. Jackson's taxable income was $22,600. What is Jackson's correct and most favorable 2021 filing status? Head of household. Married filing jointly. Married filing separately. Single.