Final answer:
The question confuses characters from different plays. In Shakespeare's 'Much Ado About Nothing', Don Pedro invites Benedick to accompany him due to their friendship and military obligations.
Step-by-step explanation:
The student's question appears to mix characters from different literary works. Don Pedro and Benedick are characters from William Shakespeare's play Much Ado About Nothing, not Don Quixote. However, if we address the question within the context of Much Ado About Nothing, Don Pedro invites Benedick to accompany him to Aragon after Claudio's wedding to continue with their military duties and also because they are good friends and comrades in arms.