Directions: Given below is a passage followed by a question. Select the option that best answers the question.

Country B has reported cases of deaths and ailing patients due to an unrecognized disease. Country B has been engaged in biological warfare with country A for 7 years. Country A had recently developed a dangerous virus, Virus X, causing symptoms of severe flu for a week in the host body, eventually leading to the death of the host. The virus only takes effect after 5 days of dormancy. The virus was deported to country B two days ago by one of their special ops. Which of the following statements weakens the doubt of Virus X being the cause of deaths in country B?