D. single- and simple multi-celled organisms
Although more complex animals like invertebrates and multi-celled organisms began to appear, it was very late compared to the original, simpler organisms for which the Precambrian time is characterized by.
<span>The epipelagic ocean zone is most habitable. taken from another sorce than my brain doe fam...</span>
Temperatures raise as the altitude increases. It also absorbs all the suns rays and energy making it warmer. <span />
