The question pertains to the authorship of a significant document titled "The Philosophy of the Bomb," which holds historical importance in the Indian freedom struggle. The document was crafted by Bhagwati Charan Vohra at the behest of another prominent revolutionary.

1. Let's understand the context: "The Philosophy of the Bomb" was a manifesto that articulated the revolutionary ethos of the Hindustan Socialist Republican Association (HSRA). It was an attempt to justify the use of violence in the struggle against the British colonial rule.
2. The available options include Ram Prasad Bismil, Sukhdev, Rajguru, and Chandrashekhar Azad. All of these individuals were noted freedom fighters and members of revolutionary groups.
3. Among these, Chandrashekhar Azad was a leading figure in the HSRA and was highly influential in its operations and strategies.
4. Bhagwati Charan Vohra wrote "The Philosophy of the Bomb" after detailed discussions with Chandrashekhar Azad. Azad's strategical leadership in HSRA was well-regarded, and his thoughts were instrumental in the development of revolutionary documents.
5. Thus, the correct answer is Chandrashekhar Azad.

Conclusively, Chandrashekhar Azad's request and ideological inputs led Bhagwati Charan Vohra to draft "The Philosophy of the Bomb," serving as a manifesto for the HSRA's cause.