34. 在室溫下，下列四種反應何者進行得最慢？(A)\(\text{Fe}^{3+}_{(aq)} + \text{SCN}^{-}_{(aq)} \rightarrow \text{FeSCN}^{2+}_{(aq)}\)(B)\(\text{Ba}^{2+}_{(aq)} + \text{SO}_4^{2-}_{(aq)} \rightarrow \text{BaSO}_{4(s)}\)(C)\(2\text{Fe}^{3+}_{(aq)} + \text{Sn}^{2+}_{(aq)} \rightarrow 2\text{Fe}^{2+}_{(aq)} + \text{Sn}^{4+}_{(aq)}\)(D)\(2\text{SO}_{2(g)} + \text{O}_{2(g)} \rightarrow 2\text{SO}_{3(g)}\)