user: Question: What is the home port of M40?
Columns: ['Navy', 'Name', 'Pennant', 'Commissioned', 'Home port']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['Royal Navy', 'Brecon', 'M29', 1980.0, 'HMS Raleigh']
SQL:

assistant: SELECT "Home port" FROM "Table" WHERE "Pennant" = 'M40';