In making an experiment their are two types of variable that should be consider, one is the dependent variable and the other one is the independent variables. I the question that dependent variable would be the result or the effect of the gender of mice and the independent is the ways in determining it. So the variables should be fair if you want your result to have no bias. Thus the answer would be letter B. because it has the same variables but different in gender
All planets have these same layers (From deepest to shallowest, inner core then the outer core, then the mantle, and lastly the crust. A good example is the Earth) that is shown in the diagram, even the sun has all the layers I just listed.
But, some planets I can think of are Mars, Venus, Moon, and the Earth of course.
Layer C. sounds like it could also represent Layer D, since they are so close.
P. S. I did my best to try to answer this.
What are the choices, mate?