The correct answer is (a) India.
The Asia Cup Hockey Tournament was held in May 2009 in New Delhi, India. The tournament was hosted by the Indian Hockey Federation (IHF) and was the 11th edition of the Asia Cup. The tournament was played in a round-robin format, with the top four teams advancing to the semi-finals. India won the tournament, defeating Pakistan in the final.
The other options are incorrect because they are not the countries where the Asia Cup Hockey Tournament was held in May 2009.
(b) Malaysia: The Asia Cup Hockey Tournament was not held in Malaysia in May 2009. The last time the Asia Cup Hockey Tournament was held in Malaysia was in 2003.
(c) South Korea: The Asia Cup Hockey Tournament was not held in South Korea in May 2009. The last time the Asia Cup Hockey Tournament was held in South Korea was in 2007.
(d) UAE: The Asia Cup Hockey Tournament was not held in the UAE in May 2009. The last time the Asia Cup Hockey Tournament was held in the UAE was in 2013.