Answer: D) Two teams, the Tomcats and the Huskies, battled for the city championship.
Explanation: an appositive phrase is a noun phrase that gives further information or explains a noun that is right before it. From the given options, the one that combines the two sentences by using an appositive phrase, is the corresponding to option D: Two teams, the Tomcats and the Huskies, battled for the city championship, where "the Tomcts and the Huskies" is the appositive phrase, because it gives information about the noun "teams."