Earth’s surface consists of rigid plates that are constantly shifting

Earth - plates moving around, showing motions deeper down
like boiling water - hot stuff comes to the top and cooler stuff goes down
can cause volcanoes (usually at plate boundaries)
BUT there's another way to get volcanoes:
hotter rock = flows more easily
this hot rock collects deep down
when you get enough, it pushes up to make a bulge (volcano) even though it's not at a plate boundary
this kind can create chains or islands of volcanoes - eg Hawaii
Then I'd go back and label my first three lines "1 way" and the rest "the other way" (meaning the passage is split into two different ways to make a volcano)

1)The answer here is D, because the text has two distinctive sections, discussing two different processes:
- volcanic activity molten lava rises from the down going plate and erupts through the overlying one
- volcanoes that appear far away from plate intersections, in the "mantle plume" situation
A is incorrect because the composition of the mantle is not discussed, rather its movements. B is also incorrect because the islands are only mentioned once as an example C is wrong because these surface plates are only discussed in the first part of the text. The second concerns that mantle plume situation, which is not a part of the "surface plates" topic. The last answer choice is similarly wrong, because this is only mentioned in the first part of the text.
or
Q1 Main idea
a couple of different ways to make volcanoes (can get this from my notes above). Answer D says almost exactly that.
Q2 inference - chain of volcanoes - I remember that's from towards the end of my notes, so I go scan the passage again.
"over a long period of time an active plume creates a chain of volcanoes"
So, if it takes place over a long period of time, those volcanoes must be different in age relative to each other. A is tempting because I remember seeing maps of volcano chains... but that's not in the passage. C is contradicted by the passage. D and E aren't discussed - I have no idea (so, therefore, I can't infer the info).
Hence B.
Q3 why does the author refer to Hawaii
From my notes - Hawaii is an example of the chain thing
A is fine until we get to "does not occur elsewhere" - this is one of the major two ways of making volcanoes
scanning down... E matches my original idea (which I developed before looking at the choices) - it's an example of how this alternate way works
Q4 specific detail - a "hot spot" is an example of what?
That's about the "hotter rock" which was also talked about in the second way (chains), so scanning the passage...
"the surface mark of an established plume is a hot spot - an isolated region of volcanoes and uplifted terrain located far from the edge of a surface plate."
So, not B. Not D - says nothing about being unique to Pacific. Need a little more info - back to the passage. So the "hot spot" is this "established plume" thing and a "plume" is the result of a reservoir of very hot rock from the mantle.
A says the reservoir is "untapped" - but if it's coming up to the surface, then we can't call it "untapped." C says the rock is under enormous pressure - and I generally believe that, but I'm not finding a place in the passage where it specifically says that.
E calls it a plume, which the passage does say, and also says it's mantle rock, which is true according to the passage. And E says that this mantle rock comes from near the core and the passage does say that this stuff comes from the "base" of the mantle and describes it as having "proximity to Earth's core." So this one looks right!