The answer would be: the ounces in a cup of milk.
Scientific notation is used to express measurements that are very small or very large. It makes bigger or smaller numbers easier to read.
So among the choices, the LEAST likely measurement would be ounces in a cup of milk because the value is neither too small or too large.
In one cup there are 8 ounces. The number 8 isn't exactly too small or too large and is very easy to read for anyone who is analyzing it.