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

How to treat tapeworms in ferrets
Check your ferrets for fleas.
Your ferret can get tapeworms by swallowing infected fleas. If your ferret is scratching, comb through his fur with a fine-toothed flea comb, which is available at your local pet store.

Select from the following. (I) The flea comb works by piercing the skin on the backside of the ferret's tooth. You may also gently prick your ferret's skin with a hangpaperclip or a paperclip at the base of his tooth to remove any stray fleas.; (II) Fleas are a skin irritant that can cause an infection. If the fleas feel a pain, itching, or stinging sensation, call your vet.; (III) Focus on the area between his shoulder blades-this is a popular' flea' spot on ferrets. If you don't see the actual fleas, you may see their residue, which is dark black.; (IV) You can put the flea comb under his skin for fleas when you first get them, but then repeat the process every day until they stop coming. Once you spot fleas and tapeworms, make an appointment to see a vet to get them off your ferret.;
(III)