Because of its accuracy in outlining the Earth's subsurface, the seism

Summary - Author is talking about Seismic-Reflection method and its importance. Then he/she provides details of the method and how it deals with various factors affecting its accuracy.

1. The passage is primarily concerned with

(A) describing an important technique – CORRECT.
(B) discussing a new method – WRONG. Not a ‘New’ method as its not mentioned in the passage that it’s new.
(C) investigating a controversial procedure – WRONG. This option is incorrect for the reason that author is not investigating any controversial procedure.
(D) announcing a significant discovery – WRONG. No author does not say anything about significant discovery.
(E) promoting a novel application – WRONG. No option is given by author.

2. According to the passage, in the seismic-reflection method all of the following have a significant effect on the signal detected by the seismic instruments EXCEPT the

After POE eliminated A, D and E. Got stuck with B and C and eliminated C for the reason that passage mentions ‘each’ n lne-3 “As each source is activated, it generates a wave train that moves… “. Assumed that ‘each’ plays a role in locating every seismic instrument.

(A) presence of unrelated wave trains – WRONG. Mentioned in passage.
(B) placement of the seismic instruments
(C) number of sources in the grid pattern
(D) nature of the reflectivity of the rock interfaces – WRONG. Refer line-4 of passage.
(E) properties of rocks through which the wave train has traveled – WRONG. ‘Rock characteristic’ mentioned in passage.

3. It can be inferred from the passage that the seismic-reflection method would be likely to yield an inaccurate physical profile of the subsurface in which of the following circumstances?

Again using POE eliminated A B and E. Stuck with C and D chose D over C with a reasoning that different sources with similar seismic records would mislead the method to generate similar profile thus inaccuracy.

(A) If the speed at which the wave train moved downward changed – WRONG. Opposite to what we require to infer. Change is necessary for a unique profile
(B) If the receiver were not positioned directly at the wave-train source – WRONG. Not mentioned.
(C) If the rock on one side of a rock interface had similar elastic characteristics to those of the rock on the other side
(D) If the seismic records obtained for the different sources in a grid were highly similar to each other
(E) If there were no petroleum deposits beneath the area defined by the grid of wave-train sources – WRONG. No deposits would also have some unique profile.

4. Which of the following best describes the organization of the passage?

After POE eliminated A B and D. After a brief thought mistook in the thick of moment elements of the method as evidence to mark E the wrong answer as correct.

(A) A method is criticized, and an alternative is suggested. – WRONG. There’s no author’s opinion.
(B) An illustration is examined, and some errors are exposed. – WRONG. Author describes and nowhere examines to expose errors.
(C) An assertion is made, and a procedure is outlined.
(D) A series of examples is presented, and a conclusion is drawn. WRONG. No conclusion is drawn.
(E) A hypothesis is advanced, and supporting evidence is supplied.