Im gonna have to say that the answer is B for this one.
Answer: I think its a laptop ? Correct me if i'm wrong :D
According to one source, a single almond will require about 1.1 gallons of water to grow, and one half-gallon carton of almond milk contains anywhere from 30 to a whopping 225 almonds.
The answer is: Difficult to control all variables except one being tested
