Andrew was exposed to the chicken pox virus as a child. What happened to that virus after it crossed the blood-brain barrier and entered Andrew's brain? a. Nothing happened at first, but the virus remained there and caused negative effects for Andrew as he got older. b. Nothing happened since the chicken pox virus cannot cross the blood-brain barrier. c. The glia in his brain engulfed the virus and then natural killer cells destroyed them both. d. Andrew's natural killer cells were able to quickly destroy it.

Answer: Option A

Explanation:

When Andrew was exposed to the virus causing chicken pox he got infected and the virus crossed the blood brain barrier.

During the early stages when Andrew was a child there will be as such no effect of the virus in the brain.

During the early stage the virus will remain in the brain and cause harm in the later days when Andrew will be older. The virus can alter the brain functions such as homeostasis, blood brain barrier functions. It enters the brain while damaging the nervous system.