Answer:
A.) Horatio can be trusted.
Explanation:
William Shakespeare's "Hamlet" revolves around the story of a young prince and his desire to avenge the death of his father at the hands of his uncle who had also claimed the throne. The play deals with themes of family, love, gender, insanity, appearance vs reality, supernatural, etc.
In Act I, it was Horatio along with Bernardo and Marcellus who first spotted the ghost of the dead king. And Horatio also revealed to the young prince Hamlet about his father's ghost. By this, Shakespeare seems to indicate that Horatio will be a trusted aide and guide to Hamlet.
Thus, the correct answer is option A.