Hope this helps!!
Answer is Shield volcanoes
Explanation: Shield volcanoes have thin or less viscous magma which has a lower amount of silica in it. Magma is a mixture of liquid rocks, crystals and minerals etc. The less viscous or thin magma leads to relatively non violent eruptions and instead the magma overflows from the vent just like water overflows from the sides of a container.
Oxytocin causes contractions during pregnancy, it also is the reason why mothers feel "motherly" towards their children after childbirth as there are high levels on oxytocin in the mother's blood.
Well, I cannot see your list of suggestions but I am assuming one of them would be muscles.
Muscles use a lot of energy and require a large number of mitochondria.