Explanation:

The correct answer is option B: Ram Chaddha. Ram Chaddha did not write about the caste system.

Explanation in detail:

E. V. Ramaswamy Naicker: E. V. Ramaswamy Naicker, also known as Periyar, was a social reformer and politician from Tamil Nadu, India. He was a prominent critic of the caste system and played a significant role in the Dravidian movement. Periyar emphasized the need for social equality and fought against caste-based discrimination.

Ram Chaddha: Ram Chaddha is not a well-known figure in the context of the caste system. There is no significant information or writings available about him regarding the caste system. Therefore, it can be inferred that he did not write about the caste system.

B. R. Ambedkar: B. R. Ambedkar was a prominent social reformer, jurist, and politician in India. He was one of the key architects of the Indian Constitution and a strong advocate for the rights of Dalits (formerly known as untouchables). Ambedkar extensively wrote about the caste system and its impact on society. He highlighted the oppressive nature of the caste system and advocated for its abolition.

Jyotiba Phule: Jyotiba Phule was a social reformer and thinker from Maharashtra, India. He is known for his efforts in fighting against social injustices, including the caste system. Phule wrote extensively about the caste system and its oppressive nature. He argued for the need to challenge and overthrow the caste-based hierarchy in Indian society.

In conclusion, among the given options, Ram Chaddha is the one who did not write about the caste system. The other three options, E. V. Ramaswamy Naicker, B. R. Ambedkar, and Jyotiba Phule, all wrote extensively about the caste system and its impact on society.