Some statements about heavy water are given below `:` `(i)` Heavy water is used as a moderator in nuclear reactors `(ii)` Heavy water is more associated than ordinary water. `(iii)` Heavy water is more effective solvent than ordinary water Which of the above statments are correct ?A. (a), (b) and (c)B. (b) and (c)C. (a) and (c)D. (a) and (b)