Independent variable represent the variable
Trisomy=3 chromosomes; 1 more than the required pair (2)
21=the type of chromosome
So, here we can eliminate A and B.
Now we have C and D.
I know that when sperm cell(s) simultaneously fertilize [an] egg, a class of identical twins will form. Therefore, we can eliminate D, leaving us with merely C. Henceforth, C is your final answer.
The Answer is
A. Black box,because black absorbs more heat than white
An example is that on a sunny day you were wearing a black t-shirt you would be sweating you bottom off but if you were wearing a white t-shirt you would be less hot and not sweating your bottom off. Why? Because black absorbs more heat rays than white does
