The functions of the State Public Service Commission of Uttar Pradesh can be. extended by

1. A

   Prime Minister

   The Prime Minister has no power under Article 321 to extend the functions of a State Public Service Commission. That is a legislative, not a PMO, act.

2. B

   Union Ministry of Personnel, Public Grievances and Pensions

   The Union Ministry of Personnel administers the UPSC and central personnel rules. It cannot by itself extend the UPPSC’s statutory functions.

3. C

   The President

   The President appoints the UPSC and, in specified cases, may relate a State Commission to Union work, but extension of a State Commission’s functions as respects State services is not keyed as a presidential act here.

4. D

   Uttar Pradesh State Legislature

   Article 321 allows an Act of the Legislature of a State to provide additional functions for that State’s Public Service Commission (including local bodies and public institutions created by law). For the UPPSC, that legislature is the Uttar Pradesh State Legislature—the official key.

Summary. Official key is (d) the Uttar Pradesh State Legislature. Article 320 lists PSC duties; Article 321 is the extra-functions clause. Union personnel ministry and the Prime Minister are administrative distractors. Do not confuse presidential appointment of members with legislative extension of functions. Honour the stored letter (d).