Mangdechhu Hydroelectric Project is a 720 MW run-of-river power plant located on the Mangdechhu River in central Bhutan. It was developed with Indian financial and technical assistance and jointly inaugurated by the Prime Ministers of India and Bhutan in 2019. Therefore, A matches with 3.

Restoration of Stor Palace refers to a historic 19th-century palace located in Kabul, Afghanistan (also known as Qasr-e-Storay). India funded its complete restoration in collaboration with the Aga Khan Trust for Culture, and it was jointly inaugurated by the leaders of India and Afghanistan in 2016. Therefore, B matches with 2.

District Hospital at Dickoya is a 150-bed multi-specialty hospital located in Hatton, Sri Lanka. It was built using Indian grant assistance primarily to serve the healthcare needs of the Indian-origin Tamil estate workers in the Central Province. Therefore, C matches with 4.

Institute of Security and Law Enforcement Studies is located in Addu City, Maldives (now officially inaugurated as the National College of Policing and Law Enforcement or NCPLE). It was constructed entirely with Indian grant assistance under a bilateral Memorandum of Understanding. Therefore, D matches with 1.

Therefore, the correct matching is A-3, B-2, C-4, D-1, which corresponds to Option B.