Answer:
The sentence that uses omission correctly is:
C. One serious omission in the team list was the name of the coach.
Explanation:
<u>Omission is a noun</u>, which allows us to eliminate option B since the sentence is using it as a verb. <u>Omission means failing to include something or someone. When you omit, you leave out, you exclude</u>. Having that meaning in mind, we can easily eliminate options A and D, since the context in those two sentences does not allow for the use of omission.
<u>Letter C is the best option. It uses omission as the noun it is, and the context and the meaning are a match. According to the sentence, leaving the name of the coach out of the team list was a serious mistake.</u>
It means that they are not essential( needed) because they rarely show anything that we have no knowledge about and that we can't solve them easily.
