You and a Friend Are in Line for a Movie

Multiple Choice

You and a friend are in line for a movie when you notice the woman in front of you sneezing and coughing. Both of you have been equally exposed to the woman's virus, but over the next few days, only your friend acquires flu- like symptoms and is ill for almost a week before recovering. Which one of the following is a logical explanation for this?

A) You have an innate immunity to that virus.
B) You have an acquired immunity to that virus.
C) Your friend does not have the ability to fight off that particular virus.
D) Answers B and C are both correct.