The word that could replace the underlined word without changing the overall meaning of the sentence would probably be nonchalant.
This refers to the editing of a text by changing the words and making it shorter but retaining its meaning.
Hence, we can see that the underlined word is not stated and there are no answer choices to choose from, I can infer that this word is "carefree" and some synonyms of this word are:
Read more about paraphrasing here:
https://brainly.com/question/24729251
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