Your answer would be C :))
hope that helped :))
Natural variation provided the phenotypes that natural selection then acted on, over time causing evolution
A baby's immune system is not fully developed until he/she is about six months-old. In the meantime, pregnant mothers pass immunoglobulin antibodies from their bloodstream, through the placenta, and to the fetus. These antibodies are an essential part of the fetus's immune system. They identify and bind to harmful substances, such as bacteria, viruses, and fungi that enter the body. This triggers other immune cells to destroy the foreign substance.
4:
Independent Variable: Photosynthesis
Dependent Variable: Starch
Starch is a product of photosynthesis. Without photosynthesis, starch cannot form. Therefore starch is dependent on photosynthesis.
5:
Independent Variable: Temperature
Dependent Variable: Animal Metabolism
Animal metabolism will only be affected if the temperature of the room changes. Therefore animal metabolism is dependent on temperature.
9:
Independent Variable: Rainfall
Dependent Variable: Thickness of growth rings
The thickness of the tree's growth rings are determined by the amount of rainfall. Therefore the thickness of growth rings are dependent on rainfall.
The main food sources of the birds( the plentiful recourses within the environment occupied by the species)