A customer complains that their wireless network drops signal when they are performing inventory in the back of their warehouse. The customer wants to cover the small area for as little money as possible. What would you recommend?

The cheapest and most effective solution you could recommend is to install a wireless repeater. A wireless repeater will do just that: It will repeat the current wireless signal and allow for extra distance. A wireless bridging system is used for connecting buildings or locations where running wire is just not possible. A mesh wireless system is probably the most expensive option, since it requires infrastructure such as a controller and lightweight WAPs. Adding just a wireless LAN controller will not add any benefit.