Write the next sentence in the following story.

How to avoid severe allergic reactions while traveling
Determine what allergens are present at your destination.
Knowledge is often the best way to prevent an unpleasant situation like a severe allergic reaction. Checking your destination to see what allergens may be present in the environment, foods, or other elements can help you avoid them and a potential reaction.

pick from the following.
1). Identify causes of your allergies. When you travel, your reactions to allergens may be quite different than those experienced by others.
2). Read your destination's website to find what may or may not be present. Always check air filters when traveling, and check the smoke detectors in populated areas, as well as any doors or windows.
3). It can also help you know what types of medications and other precautions to take. Look at the environmental conditions if you have seasonal allergies.
4). Make sure you check past travel warnings on travel websites to help you avoid certain possible allergens in the environment, such as pesticides. Your local camping store may be able to sell commercially-manufactured things for a limited fee.. The answer should be
3).