When our target is asked to make this ether startint from alkyl halides. First we recall that ethers can be prepared by substitution reactions of alkoxide anion nucleophiles with alkyl halide electrophiles- The William ether synthesis. The two ways to prepare the target ether are as follows Next we examine the two reactions to determine whether both are expected to give a good yield of the target compound. Since route A combines a strongly basic nucleophile a secondary (2^(@)) alkayl halide we expect the major product to result from elimaination by E_2 mechanism. Route B on the other hand, employs a primary alkylhalide that can not give elimination (It has no hydrogen on the beta-carbon) and that is excellent. Substrate for an S_N2substitution because it is benzylic Route B is the obvious choice. Which of the following reagents when heated will give a good yield of an ether.