Which is an example of a binary number?

The example of a binary number is accurately identified as 11100110. Binary numbers are made up of only two digits: 0 and 1. Each digit in a binary number represents a power of 2, starting from the rightmost digit, which is 2^0, moving to the left. In 11100110, every digit is either a 1 or a 0, aligning it with the definition of binary.

The other choice that appears to be related includes 11001010, which is also a binary number, comprising the digits 0 and 1, confirming its binary nature. Choice D, 1001000, follows the same criteria as both 11001010 and 11100110. However, 12345 does not qualify as a binary number because it contains digits (2, 3, 4, 5) that are outside the allowable binary digit range of 0 and 1. Thus, while all options containing 0s and 1s are valid binary representations, the correct conceptualization centers on recognizing that binary is defined solely by the presence of the two specific digits.