Consider the following reaction.
Cl₂ + H₂ → A
H₂ + Na → B
H₂ + CuO → C  + H₂O

A, B and C in the above mentioned reaction are respectively-

1. A= HCl; B= NaH₂; C= Cu₂O
2. A= HCl; B= NaH; C= Cu₂O
3. A= No reaction; B= NaH; C= Cu
4. A= HCl; B= NaH; C= Cu