Traditionally, the foundations of houses were made of concrete. A buil

Traditionally, the foundations of houses were made of concrete. A builder is experimenting with using a hard plastic polymer for foundations. A foundation made with the polymer is about the same price to construct and install as is concrete foundation. Unlike concrete, the polymer will block all water flow and is not prone to cracking with age. The builder argues that houses built with the polymer foundation will last longer.

Which of the following must be studied in order to evaluate the argument presented above?

Premise: Builder replacing TCF with PPF. The price of construction an installation of PPF is same as that of TCF. Also, PPF blocks all water flow and is not prone to cracks with age.
Conclusion: Builder argues that PPF houses will last longer.

Note: To last longer PPF has to stay intact for very long time. As water flow does not affect PPF and it does not develops cracks, there must be something that one or the other way causes damage to PPF.

A. Whether repairs to polymer foundations are more expensive than repairs to concrete foundations. - WRONG. Although it goes against the premise from price point but repair cost is not at all discussed in the passage. At best it does nothing to either the premise or the conclusion since cost of construction and installation remain same and higher repair cost doesn't impact the PPF's longer life.

B. Whether soil acidity, to which all stone is resistant, can dissolve the polymer. - CORRECT. There's new parameter that might impact the PPF in ways which breaks the conclusion apart. If PPF does not cracks great but what if it dissolves - in that case it won't last long.

C. How dry the soil in this region becomes during typical summer droughts. - WRONG. Dryness may have a linkage with water but more drier it is more irrelevant the argument becomes. So, this option does not affects the conclusion. Out of scope.

D. Whether residents will be able to smell the vapors that outgas from the polymer. - WRONG. Again smelling the outgas from polymer is out of scope as it does not affects the conclusion of PPF's longer life, not at least in ways as discussed in the passage.

E. Whether consumers seeking to buy a house will trust a house with an alternate foundation. - WRONG. Just like C and D this is also out of scope. Even if consumers don't buy the life of PPF house is longer.

IMO Answer B.