Draw the reaction of bromoethyne with 2 molecules of HBr. Name the product(s) and the type of reaction. PLEASE HELP!!

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume