In the Prayaga Prashasti, an ancient Indian text, Samudragupta is praised in glowing terms. Samudragupta was a king who ruled during the Gupta Empire, which was known for its cultural and economic prosperity. The Prayaga Prashasti was composed to celebrate his military victories and achievements.

Ashoka, another ancient Indian king, is not mentioned in the Prayaga Prashasti. Ashoka ruled during the Mauryan Empire and is famous for his conversion to Buddhism and the pillars and edicts he erected across his empire.

Harshavardhana, a king of the Vardhana dynasty, is also not praised in the Prayaga Prashasti. Harshavardhana ruled a large part of North India and was known for his patronage of art, literature, and learning.

Bindusara, the father of Ashoka, is also not mentioned as being praised in the Prayaga Prashasti. Bindusara was a Mauryan king who expanded the empire inherited from his father, Chandragupta Maurya.

Therefore, the correct answer is option 3 - Samudragupta.