Which of the words in (a), (b), (c) or (d) given below should replace the words given in bold in the following sentences to make it meaningful and grammatically correct? If the sentence is correct as it is, and 'No correction is required', mark (e) as the answer . While Arvind Panagariya has stepped down after two-and-a-half years as the vice-chairman of the NITI Aayog, to resume his academic career at Columbia University, the body that replaced the Planning Commission is still to establish itself as an authoritative voice in policy-making.