user: Question: Which position has a School of Green Valley High School?
Columns: ['Player', 'Position', 'School', 'Hometown', 'MLB Draft']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Ben Davis', 'Catcher', 'Malvern Prep', 'Malvern, PA', '1st Round - 2nd Pick of 1995 Draft ( Padres )']
SQL:

assistant: SELECT "Position" FROM "Table" WHERE "School" = 'Green Valley High School';