I believe the answer to this question would be c
Evolution of the atmosphere<span>, </span><span>the development of </span>Earth<span>’s </span>atmosphere<span> across </span>geologic time<span>. The process by which the current atmosphere arose from earlier conditions is complex; however, evidence related to the evolution of Earth’s atmosphere, though indirect, is abundant. Ancient sediments and rocks record past changes in atmospheric composition due to chemical reactions with Earth’s crust and, in particular, to biochemical processes associated with life.</span>
Z = 24 because 180 - 48 = 132 and that divided by 2 = 66 then do 180 - ( 90 + 66 ) = 24!
To keep them going and making blood pop around