Fill in the missing reactant, reagent or product from the options given below each question. a. HBr b. 1.BH_3, THF; 2. NaOH, H_2O_2 c. H_2, Pt d. 1. Hg(OAc)_2, H_2O/THF; 2. NaBH_4 e. Cl_2 a. HBr b. 1 .BH_3, THF; 2. NaOH, H_2O_2 c. H_2, Pt d. Br_2 e. None of the reagents provided can perform the desired reaction