Which of the Reactions Listed Below Would Have a Value $\Delta$

Multiple Choice

Which of the reactions listed below would have a value of $\Delta$ H° equal to zero?

A) H-H $\rightarrow$ 2H·
B) H· + CH₃-H $\rightarrow$ CH₃-H + H·
C) CH₃· + CH₃· $\rightarrow$ CH₃-CH₃
D) CH₃· + CH₃-H $\rightarrow$ CH₃-H + CH₃·
E) Reactions (B) and (D)