(i) The total number of stereoisomers possible for X is 6

(ii) The total number of diastreomers possible for X is 3 .

(iii) If the stereochemistry about the double bond in X is trans, the number of enantiomers possible for X is 4.

(iv) If the stereochemistry about the enantiomers possible for X is 2.

$ (a)\;(i) and (iii) \\ (b)\;(i) and (iv) \\ (c)\;(ii) and (iv) \\ (d)\;(iii) and (iv) $