To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) to_char - This option is correct because the to_char function in SQL can operate on any datatype. It is used to convert a value of any datatype to a character string.
Option B) max - This option is incorrect because the max function in SQL is used to return the maximum value of a specified column. It operates on numeric data types, not any datatype.
Option C) rollup - This option is incorrect because the rollup function in SQL is used to generate subtotals and grand totals in a result set. It operates on grouping sets, not any datatype.
Option D) cube - This option is incorrect because the cube function in SQL is used to generate all possible combinations of a specified set of expressions. It operates on grouping sets, not any datatype.
The correct answer is Option A) to_char. This option is correct because the to_char function can operate on any datatype and convert it to a character string.