From the words lettered A to E, choose the word that best completes each of the following sentences. The..........of the NATO countries have been alerted ab...

Answer Details

The word that best completes the sentence is "commanders-in-chief" (option C). The sentence is discussing a group of people who have been alerted about a potential attack, and the word "commanders-in-chief" refers to the leaders or highest-ranking officials of a military organization or alliance. In this case, the NATO countries are likely working together to prepare for a potential attack, so the commanders-in-chief of those countries would be the ones responsible for overseeing those preparations. The other options are not correct because "commander-in-chiefs" (option A) is not a proper plural form of the phrase, "commander-in-chief" (option B) has a typo, and "commander -in-cheif" (option D) has a spelling error.