This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to wire cable tv
Decide if you want to install a modem in your cable tv system.
A modem provides internet service through your cable system.
Choose an in-line amplifier.

Pick from:
+ In-line amplifiers are available at electronic stores. Use an in-line amplifier if your splitter has more than 2 outlets or if you intend to expand the cable wiring in the future.
+ An amplifier is a device, like a cable tv, under a faucet. The amplifier provides the same high power to your tv as a modem, but requires less power.
+ If you plan to wire it, consider renting or buying an in-line amplifier to control the function and the signal of your cable tv. The amplifier is a device that produces amplifications into an input in your television or mixer.
+ This is the muscle that plugs into the cord above the tv. You can buy a built-in amplifier from an electronics store or your isp's local hardware store.
The answer is:
In-line amplifiers are available at electronic stores. Use an in-line amplifier if your splitter has more than 2 outlets or if you intend to expand the cable wiring in the future.