1. Gary started having the symptoms of a cold the day after he went skiing with his friends. Gary doesn't understand why he was infected since he had a cold last year. Why did Gary develop a cold again this year?a. because Gary stayed out in the cold too long he when was skiing B. because a person must get a cold twice before the body becomes immune to it c. because the cold virus can reactivate in the body about once per year d. because there are many varieties of cold viruses that cause similar symptoms