B. One
because an independent variable is something you change. So in a scientific experiment you only change one thing. If you happen to change more than one thing then the test becomes unfair therefore you should repeat and make sure that only one thing is changed this time.
There has to be one side with a high concentration and another side with a lower concentration
Answer:
The majority of granitic magmas are formed by melting near the base of the continents. The magmas slowly rise through the crust like great balloons. They solidify near the surface to form gigantic bodies of igneous rock called plutons, which are exposed later when uplift and erosion remove the overlying rock.
Explanation:
