The correct answer is (a) Khangkhui Cave.
Khangkhkui Cave is a prehistoric cave located in the Senapati district of Manipur, India. The cave is known for its prehistoric cave paintings, which are some of the oldest in India. The paintings depict a variety of animals, including elephants, tigers, and deer. They also depict human figures, some of which are hunting the animals. The paintings are believed to have been created by the ancestors of the Meitei people, who are the indigenous people of Manipur.
The other options are incorrect because they are not associated with prehistoric cave paintings.
(b) Tharon Cave is a cave located in the Imphal West district of Manipur. The cave is known for its stalactites and stalagmites, but it is not associated with prehistoric cave paintings.
(c) Songbu Cave is a cave located in the Ukhrul district of Manipur. The cave is known for its natural beauty, but it is not associated with prehistoric cave paintings.
(d) Nongpok Keithelmanbi is a village located in the Imphal East district of Manipur. The village is known for its historical significance, but it is not associated with prehistoric cave paintings.