CREATE TABLE table_name_89 (head_of_household VARCHAR, married_filing_separately VARCHAR)

Name the head of household that has married filing separately of $104,426 $186,475
SELECT head_of_household FROM table_name_89 WHERE married_filing_separately = "$104,426–$186,475"
SELECT "head_of_household" FROM "table_name_89" WHERE "$104,426–$186,475" = "married_filing_separately"