The correct answer is Union Public Service Commission (UPSC).

The Union Public Service Commission (UPSC) is a constitutional body established under Article 315 of the Constitution of India. Its primary function is to conduct examinations and recruitments for various All India Services (AIS), including the Indian Administrative Service (IAS), Indian Police Service (IPS), and Indian Foreign Service (IFS), among others. These services are crucial for the administration and governance of the country at both the central and state levels. The UPSC's role ensures a merit-based selection process, aiming to recruit individuals with the necessary skills and competence for these demanding positions. It adheres to a transparent and impartial system, employing rigorous procedures to maintain the integrity of the selection process. The other options listed are important constitutional bodies, but their mandates do not encompass the recruitment of All India Services. Therefore, the UPSC holds the sole constitutional authority for this specific task. The rigorous selection process includes a preliminary exam, a mains exam and a personality test (interview). The UPSC's independence is crucial for fair recruitment and ensuring the highest standards are met.