user: Question: Which Purpose has an Elevation + Height of 0 + metres (ft), a Location of Bikini, Namu (Charlie), and a Yield of 220 kt?
Columns: ['Name', 'Location', 'Elevation + Height', 'Delivery', 'Purpose', 'Yield']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Yucca', 'Pacific Ocean', '0 + kilometres (mi)', 'Balloon', 'Weapon effect', '1.7 kt']
SQL:

assistant: SELECT "Purpose" FROM "Table" WHERE "Elevation + Height" = '0 + metres (ft)' AND "Location" = 'Bikini, Namu (Charlie)' AND "Yield" = '220 kt';