Which statement best explains why hamlet alludes to pyrrhus throughout act 3, scene ii of hamlet?

The allusion highlights the idea of avenging a father's murder.

The connection between Hamlet and Pyrrhus is the death of their fathers. Hamlet sought to avenge his father's death, as Pyrrhus was able to do so. Pyrhhus killed the murderer of his father and felt no remorse in doing so. Hamlet also feels that him killing his father's murderer would be justified. 

Astonishing means surprising