Question

although most things should be kept the same between the experimental and control groups, there is one thing that should be different. the one thing you change (or manipulate) is called the independent variable (iv). the whole point of your experiment is to see the effect of the independent variable. so, in the walrus example, the independent variable is whethre or not you feed your walruses fish food. your experimental group will get fish food, but your control group will not. that way, you can compare the two groups to see the difference fish food makes.
in the above example, what is the independent variable?
○ all of the above
○ whether or not you feed your walruses fish food.
○ the color of the eyes of the walruses
○ the age of the walruses in the experiment

Explanation:

The text clearly states that in the walrus example, the independent variable is whether or not you feed your walruses fish food. Other options like eye - color and age are not mentioned as the variable being manipulated.

Answer:

B. Whether or not you feed your walruses fish food.