To understand which mode of opening is required when the REWRITE statement is used, let's go through each option:
Option A) INPUT - This option is incorrect because the INPUT mode is used for reading data from a file, not for rewriting existing data.
Option B) OUTPUT - This option is incorrect because the OUTPUT mode is used for writing data to a file, not for rewriting existing data.
Option C) I-O - This option is correct because the I-O mode (Input-Output) is used when you want to both read and rewrite existing data in a file. The REWRITE statement is used specifically to rewrite existing records within a file.
Option D) EXTEND - This option is incorrect because the EXTEND mode is used to add new records to the end of a file, not for rewriting existing data.
Option E) All of the above - This option is incorrect because not all of the above options are required when using the REWRITE statement. Only the I-O mode is required.
Option F) None of the above - This option is incorrect because the correct answer is option C, I-O.
Therefore, the correct answer is option C, I-O. This option is correct because the I-O mode is required when using the REWRITE statement to rewrite existing records in a file.