user: Question: How many production codes did the episode number in series 46b have?
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['40a', '1a', '"Battle of the Century"', 'Norton Virgien', 'Mark Steen & Peter Hixson', 'September13,1997', '401a']
SQL:

assistant: SELECT COUNT("Production code") FROM "Table" WHERE "No. in series" = '46b';