Another step in the pp chain is a reaction in which heavy hydrogen ... ...

 Another step in the pp chain is a reaction in which heavy hydrogen combines with a proton to make a third nucleus. Which of the following shows this reaction? (The third step in the pp chain is given in problem 8.)
(A) 1H + 2H → 3He + γ
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in 16. Atomic and Nuclear Physics