karthikpandian19 wrote:The Cold War, an apt name for the nervous post-World War II relations between the superpowers, prompted families to build bomb shelters costing thousands of dollars but fortunately were never used.

families to build bomb shelters costing thousands of dollars but
X (bomb shelters) BUT Y (..were never used) are not parallel

families to invest in bomb shelters that would cost thousands of dollars and that
use of WOULD signifies BUILDING of SHELTERS will happen in future (unlike the intended meaning that building was already built in past); use of AND THAT appears a better option but IMO use of THAT WOULD COST....AND THAT ..WERE is not appropriate; WOULD COST = FUTURE but WERE = PAST - HOW come USE OF SHELTERS WERE USED IN PAST WHEN THEY ARE STILL NOT BUILT


families to invest thousands of dollars in bomb shelters that
IMO C; use of THAT near BOMB SHELTERS avoid any possible ambiguity


the building by families of bomb shelters costing thousands of dollars that
families of bomb shelters (incorrect phrase); WHAT does THAT refer - BOMB SHELTERS or thousands of dollars, making the choice ambiguous


the building of bomb shelters by families that cost thousands of dollars but

not sure WHAT is the subject of "WERE NEVER USED". If BOMB SHELTERS is subject, then we have a parallelism problem: X (bomb shelters) BUT Y (..were never used) are not parallel;

IMO C

A. No. Meaning. You need to use "that" instead of "but" at the end of this phrase to clarify what "fortunately were never used" refers to.

B. No. Verb tense. This answer choice changes the verb from "costing" to "would cost" - "would cost" is future tense and implies that the families had not yet spent the money, but according to the sentence they had spent the money on building the shelters.

C. Yes. Meaning. Without the "that," it is unclear what the phrase "fortunately were never used" refers to. It is the shelters that fortunately were never used, and this answer choice makes that clear.

D. No. Style. "The building by families" is unnecessary. Answer choice (C) is much better.

E. No. Meaning. This answer choice makes it sound like the families cost thousands of dollars.

IMO C

IMO: C