Which format specification is used to print string characters in the argument?

The correct choice is the format specification for strings, which is represented by "%s". This format is used in many programming and scripting languages, such as C, to indicate that the corresponding argument should be treated as a string. When you use "%s" in a function that formats output, it will print the string characters that the argument points to.

For example, if you have a character array or a string variable, using "%s" in a print function will display the entire string until it reaches a null terminator. This is essential for outputting text correctly and is a fundamental concept when dealing with formatted outputs in programming.

The other format specifications serve different purposes: "%d" is used for printing integer values, "%f" is used for floating-point numbers, and "%x" is used to print an integer in hexadecimal format. Understanding the correct use of these format specifiers is crucial for accurate data representation in programming.