To answer this question, you need to have knowledge of COBOL verbs. Let's go through each option to understand why it is correct or incorrect:
Option A) (A) Start - This option is a valid COBOL verb used to initiate the processing of a file or a record.
Option B) (B) Rewrite - This option is a valid COBOL verb used to modify the content of a record that already exists in a file.
Option C) (C) Delete - This option is a valid COBOL verb used to remove records from a file.
Option D) (D) Update - This option is NOT a valid COBOL verb. There is no COBOL verb called "Update" used in COBOL programming.
The correct answer is D. This option is correct because "Update" is not a valid COBOL verb.