Andrea works in an office where frequent outbreaks of colds and viruses occur. However, Andrea stays healthy most of the time and rarely misses work. Which is the most likely explanation for Andrea's health in this environment?

She has probably been taking vitamins and her co-workers have not.

She probably inherited immunity to most colds and viruses from her parents.

She probably washes her hands frequently and avoids touching her nose or mouth.

She has probably already had all the strains of colds and viruses in her office.

Question

Andrea works in an office where frequent outbreaks of colds and viruses occur. However, Andrea stays healthy most of the time and rarely misses work. Which is the most likely explanation for Andrea's health in this environment?

 She has probably been taking vitamins and her co-workers have not.

 She probably inherited immunity to most colds and viruses from her parents.

 She probably washes her hands frequently and avoids touching her nose or mouth.

 She has probably already had all the strains of colds and viruses in her office.