Question

select the best evidence to support the statement that allergies can vary in their severity. allergies are the 6th leading cause of chronic illness in the u.s...more than 50 million americans suffer from allergies each year. allergies are an overreaction of the immune system to substances that generally do not affect other individuals. these substances, or allergens, can cause sneezing, coughing, and itching. allergic reactions range from merely bothersome to life - threatening. some allergies are seasonal, like hay fever. allergies have also been associated with chronic conditions like sinusitis and asthma. anyone may have or develop an allergy from a baby born with an allergy to cows milk, to a child who gets poison ivy, to a senior citizen who develops hives after taking a new medication. adapted from national institute of environmental health sciences, \allergens & irritants\

Explanation:

The key - point is to find evidence about allergy severity variation. The sentence "Allergic reactions range from merely bothersome to life - threatening" directly shows the variation in severity of allergies.

Answer:

Allergic reactions range from merely bothersome to life - threatening.