The greenhouse effect is best described as s<span>olar radiation that is trapped by Earth’s atmosphere. Therefore, D. is the correct answer.</span>
If it is Not 3-4 Then it should be 2-1!
<span>The cell membrane acts as the gatekeeper of the cell, determining what goes in and out.</span>
A. Group of cells
Cells - Tissue - Organ ...
If you want to know more - look for "Biological Organisation"
I believe the answer to your question is c