Answer:
The correct answer is letter "C": hexadecimal.
Explanation:
The hexadecimal numeral system is composed of ten digits from 0 to 9 and six letters from the English alphabet from A to F. Letter A is given the 10 value and F values 15. Though, the decimal system composed of numbers from 0 to 9 is the most used in calculations and the binary system (composed by 0 and 1) for programming.
