user: Question: WhAt is the mArk for Grenada in group A?
Columns: ['Rank', 'Group', 'Name', 'Nationality', 'Mark']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'B', 'Brittney Reese', 'United States', '6.87']
SQL:

assistant: SELECT "Mark" FROM "Table" WHERE "Group" = 'A' AND "Nationality" = 'Grenada';