Smallpox is a virus that causes a rash that then turns into painful blisters. the last known case of smallpox was in 1977. what is the best explanation for the eradication of smallpox?

a. people are exercising more than they used to.
b. genetic testing determines who is more prone to smallpox.
c. there was an increase in antibacterial products.
d. a vaccine was developed.

Option D

Explanation: Smallpox is a virus that causes a rash that after some time turns into painful blisters. These blisters were known as small pox.

The last case of the small pox was seen in the year 1977, there were no more cases seen after this year. This is because there was a introduction of vaccine.

This vaccine was successfully introduced and small pox was eradicated because of this vaccine.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

the correct answer is b