I'm just wondering, if you have tooth decay is your only option to have teeth removed?

No... It depends on the severity of the decay. Small to moderate sized cavities can easily be filled, allowing you to keep your teeth. Some larger cavities my need more aggressive treatments such as root canals and/or crowns to save them. There are cases where the decay is large and the only choice then is to have it removed.
No. Depends on depth of decay, but often a filling is sufficient. Sometimes a root canal and or crown might be indicated to save the tooth as well. If the decay is severe enough, sometimes extraction is the only answer. A consult with your dentist can quickly determine the state of your tooth and he should provide all appropriate treatment options.
Depends. If the decay has not penetrated the nerve, then a filling can be placed so that you can keep the tooth. However, if the nerve has been penetrated and the nerve is now infected - then you may be able to remove the infection with a root canal therapy (keep the tooth), or you have elect or have no choice but to have the entire tooth removed.

Related Questions

I have tooth extraction pain and some tooth decay problems. Can you recommend some medications and treatment?

Go back to dentist. If you are still having pain after an extraction, you should return to see the dentist to have this looked at. You can also have the carious teeth examined and come up with a treatment plan to restore you teeth and mouth to a healthy condition. Read more...
See Dentist. Just because a tooth was extracted does not mean that all of your dental problems have been resolved. You need a complete dental evaluation and treatment of all of your problems, including management of the extraction site to replace the missing tooth. Read more...
See a dentist. Your problems cannot be addressed without a visual exam and xrays. See a professional asap. Read more...