Which equation represents the correct net ionic equation for the reaction between $Ca ( OH )_2$ and $H _2 SO _4$ ?
$H ^{+}+ OH ^{-} \longrightarrow H _2 O$
$2 H ^{+}+2 OH ^{-} \longrightarrow H _2 O$
$Ca ^{2+}+2 OH ^{-}+2 H ^{+}+ SO _4^{2-} \longrightarrow Ca ^{2+}+ SO _4^{2-}+2 H _2 O$
$Ca ( OH )_2+ H _2 SO _4 \longrightarrow CaSO _4+2 H _2 O$