Answer: c) An item's data type determines what legal identifiers can be used to describe variables and whether the variables can occupy memory.
Explanation: Data type is used for classification of the type and size of data and storing it in the form of text, numbers etc. They help in declaration of the variable .Example float, int, char, etc.
Thus, any variable's data type cannot be used for describing the memory space required and legal identifiers for the description that variable.
Other given statements are correct because variables is a values that can get changed in respect with the conditions and declaration of variable is made using data type, value that has been assigned , identifier, and semi-colon at the end of the statement. Thus, the correct option is option(c)