Answer:
D. An added force of 20N to the side of the hill
Explanation:
Saturated fatty acids are 'saturated' with hydrogen meaning they contain the maximum number of hydrogen. This causes them to be straight on the molecular level, allowing them to be packed close together other saturated fatty acids. Thus, they tend to be solids at room temperature. Examples of saturated fats are butter and the solid white fat you see on raw meat.
The answer is; D
This is referred to as co-evolution. It involves the reciprocal evolution of 2 species. This kind of evolution can be seen in mutualism (like the choices described above), and also predator-prey, host-parasite relationships. The term co-evolution was coined by Paul R. Ehrlich and Peter H. Raven in 1964.
