Concept:The sentence requires swapping two words to restore grammatical and meaningful usage based on their standard definitions.
Explanation:The original sentence reads: "The demographic dividend offers economic growth opportunities,
harness on investments in health, education, and skill development to
contingent the working-age population's potential."
The word "harness" means to utilise or control, while "contingent" means dependent on.
In the phrase "harness on investments", the correct word should be "contingent on investments" (dependent on investments).
Similarly, "to contingent the working-age population's potential" should be "to harness the working-age population's potential" (to utilise their potential).
Thus, interchanging B (harness) and C (contingent) makes the sentence grammatically correct and meaningful.
Answer:Option B-C (i.e., option 2) is the correct pair of words to interchange.