Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_46 (sponsor VARCHAR, winning_driver VARCHAR, date VARCHAR)

### Question ###
Who sponsored Greg Biffle's win on April 14?

### Accurate SQL ###

SELECT sponsor FROM table_name_46 WHERE winning_driver = "greg biffle" AND date = "april 14"