Introduction:
The Prayaga Prashasti is a historical inscription that was composed in the Brahmi script. It is an important document that provides valuable information about the political and cultural aspects of ancient India. It was written in Sanskrit, which was the predominant language of intellectual and literary discourse during that time.

Explanation:

1. The Prayaga Prashasti:
The Prayaga Prashasti is an inscription that was found at the confluence of the Ganges and Yamuna rivers in Prayaga (modern-day Allahabad) in Uttar Pradesh, India. It was written during the reign of Emperor Samudragupta, who was a prominent ruler of the Gupta dynasty. The inscription is dated to around 375 CE and is considered one of the earliest and most significant inscriptions of its kind.

2. Composition in Brahmi Script:
The Prayaga Prashasti was composed in the Brahmi script, which was the writing system used in ancient India. Brahmi was one of the earliest writing systems in the Indian subcontinent and was used to write various languages, including Sanskrit, Pali, and Prakrit. The inscription provides valuable historical and cultural information about the Gupta period and the reign of Emperor Samudragupta.

3. Importance of Sanskrit:
Sanskrit was the language of intellectual and literary discourse during ancient India. It was considered the language of the gods and was used for religious, philosophical, and literary purposes. The Prayaga Prashasti, being a significant inscription, was composed in Sanskrit to convey its message to a wider audience and to ensure that it would be preserved and understood for generations to come.

4. Role of Prakrit and Pali:
While Sanskrit was the predominant language of intellectual discourse, Prakrit and Pali were also widely spoken and used in various contexts. Prakrit was the language of the common people and was used in everyday conversations and literature. Pali, on the other hand, was the language used by the Buddhist community and was used to record the teachings of Gautama Buddha. Though both Prakrit and Pali were important languages during that time, the Prayaga Prashasti was composed in Sanskrit, which was the language of the elites and the educated class.

Conclusion:
The Prayaga Prashasti is an important historical inscription that was composed in the Brahmi script and written in Sanskrit. It provides valuable information about the Gupta period and the reign of Emperor Samudragupta. Sanskrit was chosen as the language of composition due to its status as the language of intellectual and literary discourse during ancient India. Prakrit and Pali, while significant in their own right, were not used for this particular inscription.