Which of the following is the most important difference between fast nuclear reactors and thermal nuclear reactors?

W) They use different fuel configurations

X) Unlike thermal reactors, fast reactors do not use a moderator

Y) Thermal reactors have a higher neutron flux than fast reactors

Z) Thermal reactors run at higher temperatures than fast reactors
X) UNLIKE THERMAL REACTORS, FAST REACTORS DO NOT USE A MODERATOR