As Many as 20% of All Americans Contract Influenza Each

As many as 20% of all Americans contract influenza each year. A sample of 400 randomly selected Americans is chosen and the number with influenza is recorded. Let X represent the number with influenza in the sample. What is the probability that between 15% and 25% of the sample is observed to have influenza?

A) 0.0052
B) 0.0062
C) 0.9876
D) 0.9948