C. Behavior
Although it does have some impact on the spread of disease, it is not a preventive measure to combat the spread of disease because it cannot be easily controlled.
EDIT: As my comment on the other answer states, this is incorrect. It is supposed to be a preventive measure, and antibiotics are not preventive, but behavior is.
B is the correct answer because none of this that you put are testable.
Answer and Explanation:
In suspension cultures (liquid media), it has been demonstrated that single cells can regenerate to form an entire plant, and undergoes all the natural stages of embryo development.
Totipotent stem cells give rise to all types of cells including the placenta and embryo in animals.Pluripotent cells on the other hand are cells that are capable of self-renewing into the three different germ layers of an embryo forming an adult without giving rise to placenta. As the embryo grows, it develops into multipotent cells.
There are a lot of human activities that gives negative effects on the earth's ecosystem but I will mention only four: Burning of things such as garbages or plants and trees, dumping of garbages anywhere, chemical substance that are being made and produced, cutting down of trees for replacement of buildings and homes. The human activities increase the occurrence of species extinction by doing this, it eliminates and destroy the homes of the species that are supposed to be living on their natural habitat. But instead of them, living peacefully, by doing these activities, their home will be destroyed that can kill them-- which can lead to extinction.