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 probably exercises more frequently than her co-workers.

She probably takes antibiotics on a regular basis.

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 probably exercises more frequently than her co-workers.

 She probably takes antibiotics on a regular basis.

 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.