The correct answer is option 'A', the Bhitari Pillar Inscription.

The Bhitari Pillar Inscription is an important historical source that provides insights into the reign of Skandagupta, one of the Gupta Empire's most powerful rulers. Skandagupta was the son of Kumaragupta I and is known for his military prowess, particularly in defeating the powerful Huna tribe.

The Bhitari Pillar Inscription is a stone pillar inscription that was discovered in Bhitari, near modern-day Varanasi in Uttar Pradesh, India. It was commissioned by Skandagupta himself and provides valuable information about his accomplishments and military campaigns.

The inscription begins with an invocation to various gods and goddesses, followed by a genealogical account of the Gupta dynasty. It then describes Skandagupta's various military victories, including his defeat of the Huna tribe.

The inscription mentions that Skandagupta successfully repelled a major invasion by the Huna tribe led by their ruler Toramana. It states that Skandagupta defeated the Huna army in several battles and drove them out of the Gupta Empire's territories.

This victory over the Huna tribe was significant as it ensured the security and stability of the Gupta Empire. The Huna tribe was a powerful and aggressive group that posed a significant threat to the northern regions of India. Skandagupta's successful defense against the Huna invasion helped preserve the Gupta Empire's dominance and territorial integrity.

The Bhitari Pillar Inscription is an important historical source as it provides valuable information about the Gupta Empire's military campaigns and Skandagupta's achievements. Through this inscription, we get insights into the Gupta Empire's military strategies, the threat posed by the Huna tribe, and the successful defense mounted by Skandagupta.

In conclusion, it is from the Bhitari Pillar Inscription that we know about Skandagupta's defeat of the Huna tribe. This inscription provides valuable historical information about the Gupta Empire's military campaigns and Skandagupta's accomplishments.

A