The correct answer is: c) Moirang Sai.
The Pena is a traditional Manipuri instrument that is played with a bow. It is made of wood and has a long, thin neck with a gourd resonator. The Pena is used to play a variety of music, including folk songs, classical music, and religious music.
The Moirang Sai is a genre of Manipuri folk songs that is traditionally sung by women. The songs are often about love, loss, and nature. The Pena is an important instrument in the Moirang Sai, and it is used to accompany the singing.
The other options are incorrect because they are not genres of Manipuri folk songs. Khongjom Parba is a Manipuri festival that celebrates the victory of the Manipuris over the British in the Battle of Khongjom. Khubak Ishei is a Manipuri religious festival that celebrates the birth of the god Krishna. Lai Haraoba is a Manipuri religious festival that celebrates the arrival of the gods in Manipur.