Suppose you needed to synthesize m-chloroethylbenzene from benzene. You could begin by chlorinating benzene and then follow

Question:

Suppose you needed to synthesize m-chloroethylbenzene from benzene.

You could begin by chlorinating benzene and then follow with a Friedel-Crafts alkylation using chloroethane and AlCl3, or you could begin with a Friedel-Crafts alkylation followed by chlorination. Neither method will give the desired product, however.
(a) Why will neither method give the desired product?
(b) There is a three-step method that will work if the steps are done in the right order. What is this method?