Final answer:
The answer to which choice is not an available string type for a column is 'INTEGER.' CHAR, VARCHAR, and TEXT are string data types while INTEGER is numerical and not meant for strings.
Step-by-step explanation:
The option that is not an available string type for a column in most database management systems (DBMS) is d) INTEGER. The types a) CHAR, b) VARCHAR, and c) TEXT are all used to store character data, which means they can hold letters, numbers, and other characters. Specifically, CHAR is used to store fixed-length strings, VARCHAR is used for variable-length strings, and TEXT is ideal for storing large blocks of text. On the other hand, INTEGER is a data type used for storing integer values (whole numbers) and is not designed for text or string data.