If a supernova (the explosion of a massive star) triggered star format

1. The primary purpose of the passage is to

(A) describe what results when a supernova triggers the creation of chains of star-forming regions - out of scope
(B) propose a modification in the most widely accepted theory of spiral-galaxy structure - Inconsistent. the author is not proposing anything
(C) compare and contrast the roles of clouds of gas and dust in two theories of spiral-galaxy structure - out of scope
(D) describe a new theory of spiral-galaxy structure and contrast it with the most widely accepted theory - at the end, he compared the new theory without DM with the existing theory of DM.
(E) describe a new theory of spiral-galaxy structure and discuss a reason why it is inferior to the most widely accepted theory - Inconsistent. He did not claim with theory is right or above another one.

2. The passage implies that, according to the new theory of spiral-galaxy structure, a spiral galaxy can be created by supernovas when the supernovas are

(A) producing an underlying density wave - out of scope. new theory does not talk about the DM
(B) affected by a density wave of spiral form - out of scope
(C) distributed in a spiral pattern - out of scope
(D) located in the central plane of a galaxy - out of scope
(E) located in a differentially rotating galaxy - can be implied according to the first para.

3. Which of the following, if true, would most discredit the new theory as described in the passage?

(A) The exact mechanism by which a star becomes a supernova is not yet completely known and may even differ for different stars. - out of scope
(B) Chains of star-forming regions like those postulated in the new theory have been observed in the vicinity of dense clouds of gas and dust. - opposite
(C) The most massive stars formed from supernova explosions are unlikely to evolve into supernovas. - If they are unlikely to form supernovas, then star formation cannot happen which would not resemble to spiral galaxy. This will discredit the new theory
(D) Computer simulations of supernovas provide a poor picture of what occurs just before a supernova explosion. - inconsistent
(E) A density wave cannot compress clouds of gas and dust to a density high enough to create a star. - out of scope. New theory does not talk about DM

4. The author's attitude toward the new theory of spiral-galaxy structure can best be described as

The word "exciting " as stated in the 2nd para shows the behavior of the author

(A) euphoric - out of scope. He is not happy or cheerful
(B) enthusiastic - the enthusiasm made him compare the new theory with the DM theory
(C) concerned - out of scope
(D) critical - out of scope
(E) disputatious - out of scope