Bunuel
The space center decided to delay the shuttle’s launch for a third time because a sensor
that gauges the fuel level of the external liquid hydrogen tank, shuts off the main engines when the tank is empty did not respond properly in tests.
A. that gauges the fuel level of the external liquid hydrogen tank, shuts
B. gauging the fuel level of the external liquid hydrogen tank shut
C. that gauges the fuel level of the external liquid hydrogen tank and shuts
D. gauging the fuel level of the external liquid hydrogen tank and shuts
E. that gauges the fuel level for the external liquid hydrogen tank shut
VERITAS PREP OFFICIAL SOLUTION:
A critical component of this problem appears past the underline as you near the end of the sentence: the verb phrase "did not respond properly in tests" requires a subject.
That subject is "sensor" (the word immediately prior to the underline), so that the streamlined sentence reads "the space center delayed the launch because a sensor did not respond properly in tests." Because of this required structure, you need everything in the underlined portion to act as a modifier for "sensor."
Choices (B) and (D) violate that need by using the active verb "shut" ("the sensor that gauges the fuel level shut down"), thereby completing the clause. The correct answer must link "shut" to "gauge" so that both verbals are part of the modifying phrase.
Choice (A) fails to properly connect the two verbals, instead completing the thought with a comma before "shuts" and leaving "shuts" unconnected to "gauges." And choice (D) is not parallel in its modifying verbs ("gauging...and shuts"), thereby creating an invalid structure.
Only choice (C), the correct choice, properly links the two verbals into one modifier.
Therefore (C) is the correct answer.