It's about estimation, so we don't need to divide. So let's round up the number to see it more clearly:
572 can be rounded up to 600, let's leave 4 as it is, since it's just one digit.
we see that 6 is bigger than 4, so the result will look like this : 1xx
so we see, it will be at least a 100, and the first digit will be in the hundred's place - that's the correct answer!