Answer:
where is option I can't see
Answer:
it is the thymus
Explanation:
this is where the t cells and b cells are made
Permian Extinction: The Permian - Triassic extinction event, colloquially known as the Great Dying or the Great Permian Extinction, occurred about 252 million years ago, forming the boundary between the Permian and Triassic geological periods, as well as the Paleozoic and Mesozoic eras.
Hope this helps!!(:
