Question

When America entered World War II in the Pacific, it was at a severe disadvantage because the attack on Pearl Harbor had destroyed most of the Pacific Fleet’s ships and planes. Even as equipment was repaired and replaced, the military struggled to relay confidential information that needed to be kept private such as troop movements, battle plans, and tactical messages; the Japanese were able to break every secret code the military developed. Their codebreaking skills put American troops at risk.
As a child, Phillip Johnson was a World War I veteran who had lived on the Navajo Nation. He knew the Navajo language was complex, unwritten, and spoken only by Navajo people. It would make the perfect code. Johnson, who was fluent in Navajo, took his idea to the U.S. Marines in San Diego, California, and in 1942, 29 Navajo Code Talkers began training.
[A] The Code Talkers had to be fluent in both English and Navajo. [B] The initial code kept only 211 terms and later expanded to 411. [C] Since Navajo has no military terms, new ones were created using traditional words. For example, the Navajo Code Talkers used “bird carrier” for aircraft and “ironfish” for submarine. [D]
The Code Talkers had been exceeding expectations. During a trial run of the test of their skills, a trained team translated an original message into Navajo Code, transmitted the message to another station, and retranslated the code back into English in under three minutes; soldiers who used the old codes required nearly three hours to complete the same task. From then on, the Code Talkers were used during every major military operation in the Pacific Theatre. [*]
Which choice is the clearest and most precise in context?
Elimination Tool

Select one answer
A
No Change
B
for the testing of
C
that tested
D
for the purpose of testing

Answers

GPT-4o mini
The clearest and most precise option in context is **C: that tested**.

This phrasing directly conveys the purpose of the trial run without unnecessary complexity, providing a straightforward connection to the skills being evaluated. The other options either add unnecessary words or are less straightforward.