Final answer:
The sentence about Renaissance artist Michelangelo should use "1475, and he" to properly connect the two clauses.
Step-by-step explanation:
The correct option that makes the sentence about Michelangelo, an artist of the Italian Renaissance, complete is "1475, and he." This option is needed because it connects two independent clauses into a compound sentence, which is grammatically correct. The complete and corrected sentence would then be: "Michelangelo, an artist of the Italian Renaissance, was born in Caprese in 1475, and he became an apprentice when he was a teenager."