So where the "following" at?
The heat released from fission reactions is used to change water into steam. The steam then turns the blades of a turbine to generate energy. The answer will hence be B. Quickly moving neutron coming out of the reaction are slowed down by water. The water heats up and turns into steam. The steam turns the turbine and produces electricity.
When cohesive force is stronger than the adhesive force: concave up meniscus, water forms droplets on surface