What was one of the significant cultural impacts of Kapilendra Dev's victories…

Concept: A passage-based "impact" question is settled only by what the passage itself asserts. The correct statement must name a consequence that the passage explicitly ties to the stated cause, while any statement that reverses, overstates, or contradicts the passage is ruled out.

Application: The passage sets out a chain of events. Kapilendra Dev's victories in a number of battles created an atmosphere of self-confidence in the Oriyas as a heroic nation, and they then directed their attention to improving their language and literature; the passage records the result as the emergence of a great poet, Sarala Das. It adds that the king encouraged his people to write in Oriya, himself included an Oriya poem in his Sanskrit work Parashurama Vyayoga, accepted Oriya as the state language in place of Sanskrit and Tamil, and issued a number of royal orders in Oriya.

So the cultural impact that the passage attributes to his victories and to the unification of people of many languages is the encouragement of literary composition in Oriya.

Cross-check against the other statements:

• The decline of the Oriya language runs against the passage, which describes Oriya being improved by its poets, written in by the people, and raised to state-language status.

• The rise of Sanskrit language runs against the passage's statement that Oriya was accepted as the state language in place of Sanskrit and Tamil.

• The prohibition of all regional languages has no basis in the passage, which records the promotion of one regional language and the unification of people of many languages under one administration.

Result: the encouragement of Oriya literary composition is the cultural impact that the passage supports.