**Explanation:**

The correct answer is option D, Ras Behari Ghosh.

1. **Aurobindo Ghosh:** Aurobindo Ghosh was an Indian nationalist, philosopher, yogi, poet, and politician. He was a key figure in the Indian independence movement and played a crucial role in the revolutionary activities against British rule in India. Aurobindo Ghosh is known for his extremist views and militant nationalism.

2. **B.C. Pal:** Bipin Chandra Pal, also known as B.C. Pal, was a prominent Indian nationalist and one of the triumvirate of Lal Bal Pal, along with Lala Lajpat Rai and Bal Gangadhar Tilak. He was a strong advocate of militant nationalism and played an active role in the Swadeshi movement and the fight against British rule.

3. **B.G. Tilak:** Bal Gangadhar Tilak, also known as Lokmanya Tilak, was a prominent Indian nationalist, social reformer, and freedom fighter. He advocated for Swaraj or self-rule and played a key role in the Indian independence movement. Tilak was known for his militant nationalism and his famous slogan "Swaraj is my birthright and I shall have it."

4. **Ras Behari Ghosh:** Ras Behari Ghosh was a lawyer and politician from Bengal. He was one of the founders of the Indian National Congress and served as its President in 1904. While he was a prominent figure in the Indian independence movement, he was not known for his militant nationalism. Ghosh was seen as a moderate leader and worked towards a more constitutional and peaceful approach to achieve independence.

In conclusion, out of the given options, Ras Behari Ghosh was not a militant nationalist. While Aurobindo Ghosh, B.C. Pal, and B.G. Tilak were all known for their militant nationalism and active involvement in the revolutionary activities against British rule, Ghosh took a more moderate and constitutional approach towards independence.