Bill (6), their son, lived with Carol the entire year. Carol has waived

Bill (6), their son, lived with Carol the entire year. Carol has waived her right to Bill’s exemption for 2015 by signing Form 8332. Jackson and Carol together provided more than 50% of Bill’s support. Jackson’s wages were $37,000; Carol’s were $15,000; Bill’s gross income was $0. Jackson’s taxable income was $22,900.

What is the taxpayer’s correct and most favorable 2015 filing status?