Which one of the following is most similar in meaning to the word ‘ contentious’ as mentioned in the passage?

Read the following passage carefully and answer the questions given below them. Certain words/phrases have been printed in bold to help you locate them while answering some of the questions. The Social Attitude Research India survey conducted in Delhi, Mumbai, and Rajasthan and UP recently does not throw up any significant surprises. It shows that close to two-thirds of the population in rural Rajasthan and rural Uttar Pradesh practice un-touchability and half the same population is opposed to Dalit and non-Dalit Hindu marriages. In fact, the respondents favored a law which would prevent such marriages. While caste prejudices are very hard to erase in a rural milieu, what should be equally worrying is that they are still very much prevalent in urban areas and institutions. We saw evidence of this in the Rohit Vemula case in Hyderabad University and in the Kanhaiya case in JNU. The easiest answer is the quota system for Dalits in institutions of higher education, government jobs, and local governments and so on. This is contentious because critics will argue that this gives an unfair advantage to the better off among Dalits, reinforces caste and goes against the merit principle. The better option would be to address the problem at the primary education level. The public education system should be re-oriented to ensure that Dalit children enrol and stay in schools. Education is a cost-effective tool to ensure that disadvantaged children get a more equal footing in later life. The other method would be to have more robust implementation of poverty alleviation schemes for Dalit families. Studies have shown that those who attend schools undergo a generational transformation in their aspirations and their confidence. The main aim should be to enable Dalits to compete under their own steam . For regressive concepts such as untouchability to vanish, it is politics that must change first, mindsets will follow.