Multi-choice problem: Continue writing the next sentence in this paragraph:

How to install a banister
Purchase a banister at a home-improvement store or on the internet.
Determine the correct height for the banister.
Contact your local building department for the codes that govern the installation of banisters.

Select from the following.
+House inspection mandates that the banister be 18 inches (46 cm) high. The higher the height, the more powerful the banister will have to be.;
+Refer to the blueprints that you made and choose the appropriate height. Pick out the type of banister you will need.;
+Mark the wall adjacent to the top and bottom stairs with the correct height. Stand a level vertically to ensure the accuracy of your markings.;
+Each home improvement store may have codes that you can call. Only judge the heights of the stairs, rather than the lengths at which they should be mounted.;
Mark the wall adjacent to the top and bottom stairs with the correct height. Stand a level vertically to ensure the accuracy of your markings.