Final answer:
The dependent clause should be added to the beginning of sentence 1, forming a complex sentence that begins with 'Even though he had not played in over a year,' followed by the main clause. The correct option is 1.
Step-by-step explanation:
The best way to add the dependent clause “Even though he had not played in over a year” to sentence 1 is to place it at the beginning of the sentence, resulting in: Even though he had not played in over a year, Will wanted to make the school baseball team.
This option clearly connects Will’s desire to make the team with the information that he hasn’t played recently, without interrupting the flow of the main clause. It also correctly uses a comma to separate the dependent clause from the main clause, following standard grammatical rules for complex sentences. The correct option is 1.