The correct answer is - D) covered by warm shallow seas.
The fact that the crinoids are have an abundance in the fossil records in Pennsylvania in the Mississippian Period, tells us that this area was covered with shallow and warm seas. The reason why we can get that conclusion is that the crinoids live only in that kind of environment, so it simply a logical conclusion.
The geological data is also confirming this, as it is easily noticeable in the layers that during this period of the geologic past, what is now Pennsylvania, was covered with shallow sea waters. Also, this waters were warm too, as the climate was warm and humid and that period, so it was a perfect environment for the crinoids to flourish.
I would say that the brain stem would automatically send a message to the muscular rib cage & your diagphragm to make them work harder.
Hope this helps :))
Answer:
To quote another answer I seen from this same question "I would say that the theme which is reinforced in this excerpt is impossibility of certainty - Hamlet is uncertain what he should do next, and he expresses that uncertainty in this soliloquy. "
Explanation:
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They reproduce by pollination.
Simple but very simple question. Cellulose.