Stellar objects are dynamic systems involving a symbiotic relationship

Hi there. I am not a verbal expert, but I want to practice myself. So I will try to explain my understand. Please help me fix if I am wrong in some points.

The first question ask about which one is not true of all stars. So from my understand, I have to understand the overall structure so that I can find the location where there are details that tell me about info of every stars, not just one type of stars. The structure of each paragraph will be like
- Para 1&2: common characters of all stars
- Para 3: white dwarf
- Para 4: the neutron star
- Para 5: black hole

How I know it?
- The last sentence of 2nd paragraph is "The three final forms a star can hold are a white dwarf, a neutron star, or a black hole." So I can think that OK after this they may tell about these 3 final form
- And yes they tell about it in each paragraph! We can easily spot from the last word of each para 3&4&5

So now I know that I have to look into para 1&2 in order to get answer since these paragraphs talk about overall stars details.

For me this question is hard, but OK, let's look at the choices
1. According to the passage which of the following is not true of all stars?
(A) They generated helium as a product of thermonuclear fusion.
So it basically says that Thermo -> Helium. In para 2, it says "In a live star, the hot center allows hydrogen to fuse into helium," so it means that the star makes helium. I'm not sure about thermo thing, so it is not 100% right but not wrong either. So I keep it but partly eliminate.
(B) They rely on internally produced pressures to counteract the effects of gravity on their own mass.
So it says that pressure something counteract the gravity. In para 1, it talks about thermo that support stars against gravity, and pressure counteract gravity. So for me I eliminate this choice since it is mentioned. Eliminate.
(C) They possess cores hot enough to combine nuclei.
it does say about "Thermonuclear fusion, the thermally-induced combining of nuclei " which has combine nuclei? So I am not sure but think that this not gonna be a right answer.
(D) They eventually produce iron cores through thermonuclear burning.
So my understand is that it says that the stars produce ironcore through thermo, which mean that both ironcore and thermo have the action in the same moment. At first I see that, OK, it talks about iron cores. But when I look closely, it says "This thermonuclear burning continues until it produces an iron core at the heart of the star. ". This means that thermo thing continues until it the ironcore is produced, which means that it is not happened at the same time. For me, this choice is very convincing.
(E) Their ultimate form is related to the mass they possess as they begin to die
OK. This choice is stated very clear in the sentence "the ultimate fate of a star depends upon its remaining mass". Eliminate.

So now I got A,C, and D left. But in A,C though i cant find the right explanation, I think that with my current resource, I could eliminate the choices. But in D, it is obvious that the info is not correct. So D is the right answer.


On the second question, this one looks a lot more easy to me.
2. The primary purpose of the passage is to
(A) present a commonplace idea and its inaccuracies; ok it does present idea. But does it mention about inaccuracy? NO. so Eliminate.
(B) explore the implications of a finding; Firstly, it doesnt say that this is a "finding". And it is not "implication", just more of normal information. Eliminate.
(C) propose a hypothesis for unexplained observations; No hypothesis at all. And no mention about unexplain. Eliminate.
(D) analyze a frequent source of misunderstanding; Didn't see any words talk about "misunderstanding" or "frequent source" Eliminate.
(E) describe a process and its outcomes; It says about process of many things (when it says that something is like this, then it will...,then it begins...,then it continues... For me these are clues of "process"). And the "outcomes" are obvious. It talks about 3 outcomes and do describe each in para 3&4&5. So YES we choose this.

PS. in the first question is kind of tough for me. Any experts please give suggestions.