Why does the following S_N2 reaction of a 1° bromide by alkynide fail to give the desired product?

Due to the presence of a poor leaving group, a substitution reaction will not occur.

Due to the presence of an acidic alcoholic proton in the substrate, an acid-base reaction will occur instead of a substitution reaction.

Due to the presence of an aprotic solvent, an S_N2 reaction is not feasible.

None of these.