user: Question: What was the surface that was played on during the week of March 16?
Columns: ['Tournament', 'Surface', 'Week', 'Winner and score', 'Finalist', 'Semifinalists']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Indian Wells', 'Hard', 'March 9', 'Marcelo Ríos 6–3, 6–7(15), 7–6(4), 6–4', 'Greg Rusedski', 'Thomas Muster Jan-Michael Gambill']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Week" = 'March 16';