It is now established that the MilkyWay is far more extended

1. ​​​The passage as a whole is primarily concerned with

(A) analyzing a current debate - No Debate has been mentioned.
(B) criticizing a well-established theory - No theory is being Criticized.
(C) showing how new facts support a previously dismissed hypothesis - No Dismissed Hypothesis is being discussed
(D) stating a conclusion and adducing evidence that may justify it - Correct - Conclusion Most of the Milky Way’s outlying matter must be dark.. Passage provides evidence for the Conclusion.
(E) contrasting two types of phenomena and showing how they are related - 2 Types of Phenomena are not mentioned.

​2. According to the passage, a bright part of a galaxy typically includes

(A) dwarf galaxies and clusters of stars - Wrong
(B) a balanced mixture of old and new stars - Out Of Scope
(C) a large portion of the galaxy’s mass - Wrong
(D) part of the corona of the galaxy - Wrong
(E) gases such as hydrogen and carbon monoxide - Correct - Given in the Passage gaseous matter such as hydrogen and carbon monoxide that are characteristic of the bright parts of a galaxy.

3. ​​​​​It can be inferred from the passage that, compared with what they now think, until fairly recently astronomers believed that the Milky Way

(A) was much darker - Wrong
(B) was much smaller - Correct - Given in the Passage It is now established that the MilkyWay is far more extended
(C) was moving much more slowly - Out Of Scope
(D) had a much larger corona - Wrong
(E) had much less gaseous matter - Out Of Scope

4. ​​​​​​​​The passage presents which of the following as incontrovertible?

I.​The low luminosity of old stars - Mentioned in the Passage old stars are not highly luminous.
II.​The absence of clouds of gaseous matter from the corona of the Milky Way - Not Mentioned
III.​The predominance of globular clusters and dwarf galaxies in the corona of the Milky Way Similar Words, but not mentioned in the Passage
(A) I only - Correct
(B) III only - Wrong
(C) I and II only - Wrong
(D) II and III only - Wrong
(E) I, II, and III - Wrong