Answer:
Cancer disease occurs when the abnormalities occurs during cell division of stem cells. Stem cells are those cells which are produced in the body and used by the body when the cells are older or get damaged. When the division of these stem cells are uncontrollable, cancer occurs which spread to the surrounding cells. When a large group of cancer cells grow in size, it turns into tumor.
<span>A soil horizon is a layer parallel to the soil surface</span><span>, whose physical characteristics differ from the layers above and beneath</span>
Not enough info, but I'd go with:
B) hydrogen peroxide
