Calculated fields in Siebel are computed values that cannot be directly queried because they don't exist as stored columns in the database. They are calculated on-the-fly when displayed. They can be used as sort criteria (option A is false). They are read-only (option C is true, not false). Since option C says something false is 'false', it's incorrect. The question asks for the FALSE statement, and B correctly identifies that querying on calculated fields is not allowed.