Which of the following numbers is a multiple of 8

Well I cant see what your possible answer choices are, but multiples of 8 are numbers that can go into 8 evenly without having a remainder. Some multiples of 8 include but not limited to 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, ... etc.

Some options were needed.

But some general information about multiples of 8 may be helpful for you to find out which of the options is the correct.
A multiple of a number, when divided by that number results in a whole number with no rest. So, any number that can be divided by 8 and the result is a whole number, then that's a multiple of 8.