Explanation

Reading the question: we see boldfaced sentences, so we're certain that the question will involve identifying the logical roles of the sentences. We confirm this by checking out the question stem. Then we will go through the argument and identify the logical role of each sentence, not bothering to analyze the argument further.

Sentence

Starts With.../Includes...

Function

1st

"3D printers have an application"

Evidence, evidence

2nd

"However, suitability for prototyping"

Partial contradiction

3rd

"3D printers have this natural application"

Support to the partial contradiction



Creating a filter: the word "however" signals a shift in perspective. Both boldfaced portions are supporting statements; the first supports the first opinion (which is implicit), and the second supports the second opinion, which contradicts the first to some degree. We have our answer prediction.

Applying the filter: (A), (D), and (E) all express the statements as on the same side of the argument, so they are all out. We're left with (B) and (C). We can see (B) is wrong because of its latter portion; the second boldfaced statement does not express a position, but rather an explanation supporting the second position. So (C) must be the answer. We can confirm this. The "position that the argument seeks to establish" is that 3D printers can function as a production line. Indeed, the first statement is the basis for the first opinion, the objection to the idea that the 3D printers can be the production line. And the second, though we might not have phrased it in this way, is a consideration that is introduced to counter of the force of that evidence--namely, they can be mass-production even though they are good at prototyping. The correct answer is (C).