Which of the Following Reactions Is the Most Likely to Be

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

A) H₂(g) $\rightarrow$ 2 H(g)
B) 2 F(g) $\rightarrow$ F₂(g)
C) C(s) $\rightarrow$ C(g)
D) CCl₄(g) $\rightarrow$ C(g) + 4 Cl(g)
E) HCl(g) $\rightarrow$ H(g) + Cl(g)