That would be 1/4.
God second grade and fractions.
My sister (now retired) taught math to middle and high school kids in a magnet school in Baltimore. Most of the students were dumb as rocks. Most could not answer that simple question without physical aids. You would not believe how stupid most of them were.
If you really wanted to confound them, ask them to divide 1/2 by 1/4. Most would answer “You can’t do that. That’s impossible. That doesn’t make any sense.”
You think that’s bad, try asking a college student which is smaller, 0.1 or 0.08. They probably won’t know. They all say everything works backwards to the right of the decimal - but then they can’t explain what that means.