What is the following in Arabic numbers xc?

The Roman numeral "XC" is a combination of the letters "X" and "C." In Roman numerals, "X" represents the value of 10, and "C" represents the value of 100. When a smaller numeral precedes a larger numeral, it indicates subtraction. Thus, "XC" means 100 - 10, which equals 90. Therefore, the value represented by "XC" in Arabic numbers is indeed 90, confirming the correctness of the choice provided.