Short Answer 
The allusion to Pyrrhus and Priam in Hamlet enhances themes of revenge and justice, paralleling Hamlet’s emotional struggles with vengeance. This reference reinforces the tragic consequences of seeking revenge, notably in relation to King Hamlet’s murder, supporting option A as a key interpretation.
Step 1: Understanding Allusion
In literature, an allusion is a reference made to a person, place, event, or piece of literature that is well-known but not directly mentioned. It serves a purpose by helping the audience make connections with the text. In this case, Shakespeare uses the story of Pyrrhus and Priam as an allusion in Hamlet, which enhances the themes of revenge and justice.
Step 2: Relation to Hamlet’s Themes
The allusion to the story of Pyrrhus and Priam specifically reflects the theme of revenge in Hamlet. Pyrrhus seeks to avenge his father’s death just like Hamlet wishes to avenge King Hamlet’s murder. This connection emphasizes the emotional struggles of Hamlet as he grapples with the moral implications of revenge and justice in the royal context.
Step 3: Conclusion and Significance
Ultimately, the allusion enriches the narrative by paralleling Hamlet’s quest for revenge with Pyrrhus’s actions. This reinforces the thematic link between the two stories, which underscores the tragic toll of seeking vengeance. The correct interpretation of the allusion in Act II, Scene ii is that it vividly highlights ideas that tie back to the murder of King Hamlet, thus, supporting option A as the best explanation.