What role do the cadmium control rods play in a fission reactor?
a.The cadmium combines with spent uranium fuel to produce a non-radioactive product.
b.The rods focus the neutrons toward the center of the reactor.
c.The cadmium acts as a catalyst, enabling fission to occur at lower temperatures.
d.The rods control the rate of fission by absorbing neutrons.
e.The rods move forward and backward, driving the pistons that turn the turbines