Concept:Word stress refers to the syllable that is said with the greatest emphasis when pronouncing a word.Explanation:The word "population" is made up of four syllables: pop-u-la-tion.In standard pronunciation, the main stress falls on the third syllable, which is "LA".Therefore, the correct way to mark the stressed syllable is po-pu-LA-tion.The remaining options place the emphasis on the first, second, or fourth syllable, which does not match the correct pronunciation.Answer:C. po-pu-LA-tion