Concept:The correct word must be the opposite of "dissuade" and complete the meaning of the sentence.Explanation:"Dissuade" means to persuade someone not to do something, or to discourage them.The sentence contrasts two sets of teachers: some discourage students from Mathematics, while others encourage them."Motivate" means to give someone a reason or encouragement to act.Thus, "motivate" is the most nearly opposite in meaning and fits the gap correctly.Answer:A. motivate