Concept:A relative pronoun must fit the noun it refers to and its role in the clause.
For a person acting as the subject, the correct pronoun is "who".
Explanation:The clause following "aunt" is "____ spoke to us".
The missing pronoun is the subject of the verb "spoke".
This is because the aunt is the one who performed the action of speaking.
Thus, we need a subject relative pronoun, not an object pronoun.
"Whom" (Option D) is the object form, so it cannot be used here.
"Which" (Option B) refers to animals or things, not people.
Although "that" (Option A) can sometimes be used for people, "who" is the standard and most appropriate pronoun for a specific person acting as the subject.
Therefore, the sentence reads: "His aunt who spoke to us lives in Tamale."
Answer:C. who