B. Second level consumer because it is not a plant(producer). It is not a decomposed and it is eating the mouse , a first level consumer .
The answer is; cancer occurs due to unregulated cell division
This causes them to proliferate causing a mass of cells and affect neighboring tissues. The cells are usually undifferentiated and therefore do not function properly as tissue. This unregulated division is due to malfunction of the tumor suppressor gene that is significant in cell cycle regulation and apoptosis.
