The correct answer is 111. The decimal system is base-10, which means that each place value represents a power of 10. The number 111 is composed of one hundred (10^{2), plus one ten (10}1), plus one (10^0), which equals one hundred and eleven. The other options use either binary (1011011), hexadecimal (6F), or a mix of digits not applicable to the decimal representation of the number one hundred and eleven.