user: Question: Which Opponents have a Team of Arsenal, and a Year of 1963–64?
Columns: ['Year', 'Team', 'Progress', 'Score', 'Opponents']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1955–58', 'Birmingham City', 'Semi-finals', '1–2 (Playoff)', 'Barcelona']
SQL:

assistant: SELECT "Opponents" FROM "Table" WHERE "Team" = 'Arsenal' AND "Year" = '1963–64';