Pick up the wrong statement | Mechanical Engineering

(a)    In a heterogeneous or solid-fuel reactor, the fuel is mixed in a regular pattern within moderator.
(b)    Slow or thermal neutrons have energy of the order or 0.025 eV
(c)    Fast neutrons have energies above 1000 eV
(d)    Fast reactor uses moderator
(e)    Most serious drawback in using water as coolant in nuclear plants is its high vapor pressure.

Ans: d