The founder of the Nair Service Society (NSS) was:

Mannathu Padmanabhan
Vakkom Moulavi
Chattampi Swamikal
Thycaud Ayya

The correct answer is A) Mannathu Padmanabhan.

Mannathu Padmanabhan was a social reformer and freedom fighter who founded the Nair Service Society (NSS) in 1904. The NSS is a socio-cultural organization that works for the upliftment of the Nair community in Kerala, India.

B) Vakkom Moulavi was a Muslim scholar and reformer who fought for the rights of Muslims in Kerala. He was the founder of the Majlis-e-Ittehadul Muslimeen (IUML), a political party that represents the interests of Muslims in Kerala.

C) Chattampi Swamikal was a Hindu spiritual leader and reformer who fought against caste discrimination. He was the founder of the Sree Narayana Dharma Paripalana Yogam (SNDP Yogam), a social reform organization that works for the upliftment of the Ezhava community in Kerala.

D) Thycaud Ayya was a social reformer and freedom fighter who worked for the upliftment of the backward classes in Kerala. He was the founder of the Sree Narayana Gurukulam, a school that provides education to the underprivileged.