केन्द्रीय सेवे संबंधातील अतिरिक्त कार्ये संघ लोकसेवा आयोगाकडे _______ द्वारे सुपुर्त केली जावू शकतात.

The correct answer is Option C (Parliament).

Key Points:
• Constitutional Provision for Additional Functions:
• Article 321 of the Constitution empowers the Parliament to provide for the exercise of additional functions by the Union Public Service Commission (UPSC) regarding the services of the Union.
• The text specifies: 'An Act made by Parliament may provide for the exercise of additional functions by the Union Public Service Commission or the State Public Service Commission as respects the services of the Union or the State and also as respects the services of any local authority or other body corporate constituted by law or of any public institution.'
• The President (Article 320) makes regulations specifying matters where consultation with UPSC is not necessary, but conferring *additional functions* is an exclusive legislative prerogative of Parliament.
• Key Takeaway: Under Article 321, Parliament may confer additional functions on UPSC by law.