The correct answer is A. recommend.
The other options are incorrect because they do not accurately reflect the meaning of the sentence.
B. restore: to bring back to a former state
C. encourage: to give support or encouragement to someone or something
D. reinstate: to put someone or something back in a position of power or authority
The sentence is about the primary duty of our countrymen at present. The word “curb” means to control or stop something from happening. In this context, it means that our countrymen should control or stop social evils such as casteism and untouchability.
The word “recommend” means to suggest that someone do something. In this context, it means that our countrymen should suggest that others control or stop social evils such as casteism and untouchability.
The word “restore” means to bring back to a former state. In this context, it does not make sense to say that our countrymen should bring back social evils such as casteism and untouchability.
The word “encourage” means to give support or encouragement to someone or something. In this context, it does not make sense to say that our countrymen should give support or encouragement to social evils such as casteism and untouchability.
The word “reinstate” means to put someone or something back in a position of power or authority. In this context, it does not make sense to say that our countrymen should put social evils such as casteism and untouchability back in a position of power or authority.