Which of the Following Reactions Is the Most Likely to Be

Multiple Choice

Which of the following reactions is the most likely to be endothermic?

A) 2 Na(s) + 2 H₂O(l) $\rightarrow$ 2 Na⁺(aq) + 2 OH^-(aq) + H₂(g)
B) 2 Mg(s) + O₂(g) $\rightarrow$ 2 MgO(s)
C) 2 NaCl(s) $\rightarrow$ 2 Na(s) + Cl₂(g)
D) Na⁺(g) + e^- $\rightarrow$ Na(g)
E) Cl₂(g) + 2e^- $\rightarrow$ 2 Cl^-(g)