Identify the incorrect statement regarding heavy water :

Question

$\begin{array}{1 1} (1) It\; reacts\; with\; Al_4C_3\; to \;produce\; CD_4\;and\; Al(OD)_3 \\ (2) \text{It is used as a coolant in nuclear reactors.} \\ (3) It\; reacts\; with\; CaC_2\; to\; produce\; C_2D_2\;and\; Ca(OD)_2 \\ (4)It\; reacts\; with\; SO_3\; to\; form\; deuterated\;sulphuric\; acid \;(D_2SO_4). \end{array}$