Who was the religious and social reformer who founded the Arya Samaj movement in nineteenth-century India?

Introduction / Context:
The nineteenth century in India saw the rise of several religious and social reform movements that challenged practices like superstition, caste discrimination and idol worship, and promoted education and social upliftment. Arya Samaj was one such influential movement that called for a return to the teachings of the Vedas. Examinations frequently ask about its founder, making this a high value general knowledge fact.

Given Data / Assumptions:

• The organisation mentioned is Arya Samaj.
• The question asks for its founder.
• The options present various Indian leaders and reformers: Acharya Narendra Deva, Dayanand Saraswati, Raja Ram Mohan Roy, Acharya Vinoba Bhave and Swami Vivekananda.
• We assume standard accounts of Indian social and religious reform history.

Concept / Approach:
Arya Samaj was founded by Swami Dayanand Saraswati in 1875. His motto was "Back to the Vedas", and he strongly opposed practices such as idol worship, caste based discrimination and blind rituals. Other reformers in the options are associated with different organisations and movements, so the key is to correctly pair each name with the movement they led and then select the one linked to Arya Samaj.

Step-by-Step Solution:
Step 1: Recall that Arya Samaj is a Hindu reform movement emphasising Vedic teachings and social reform.Step 2: Identify Swami Dayanand Saraswati as the monk and thinker who launched this movement in Bombay (now Mumbai) and later expanded it.Step 3: Check the other names: Raja Ram Mohan Roy is remembered as the founder of the Brahmo Samaj; Swami Vivekananda is associated with the Ramakrishna Mission; Vinoba Bhave is linked with the Bhoodan movement.Step 4: Recognise Acharya Narendra Deva as an educationist and socialist leader, not the founder of Arya Samaj.Step 5: Conclude that Dayanand Saraswati is the correct answer.

Verification / Alternative check:
To verify, we can recall the slogans and writings of each leader. Dayanand Saraswati wrote "Satyarth Prakash" and repeatedly called for Vedic reform, which is central to Arya Samaj ideology. Raja Ram Mohan Roy focused on monotheism and opposed sati through Brahmo Samaj. Swami Vivekananda took Vedanta and yoga to the West and established the Ramakrishna Mission. These distinct identities confirm that only Dayanand Saraswati fits the question.

Why Other Options Are Wrong:
Acharya Narendra Deva was a prominent political and educational figure but did not found Arya Samaj. Raja Ram Mohan Roy's reform work predates Dayanand Saraswati and is centred around Brahmo Samaj instead. Acharya Vinoba Bhave gained fame for leading the Bhoodan (land gift) movement, not for religious institutional reform. Swami Vivekananda, although a towering spiritual figure, is linked with the Ramakrishna Mission rather than Arya Samaj. Therefore, they are all incorrect in this specific context.

Common Pitfalls:
Students often mix up social and religious reformers because they are studied together in the same chapter. A common mistake is to associate every nineteenth century reform body with either Raja Ram Mohan Roy or Swami Vivekananda just because their names are very familiar. To avoid confusion, it is useful to memorise key pairs: Brahmo Samaj Raja Ram Mohan Roy, Arya Samaj Dayanand Saraswati, Ramakrishna Mission Vivekananda, and Bhoodan Vinoba Bhave. This mapping simplifies many GK questions.

Final Answer:
The correct answer is Dayanand Saraswati.