Answer:
If Tim wants his readers to understand what makes Gerardo unique, the idea he should include is:
1. Gerardo speaks three languages.
Step-by-step explanation:
We can find the correct answer through elimination. Options 2, 3, and 4 are not about characteristics that make Gerardo unique. Actually, they are about things Gerardo and Tim have in common, characteristics that they share. To indicate Gerardo's uniqueness, Tim must mention something different about him, something that distinguishes him from others, including from Tim himself. In that case, the best option is number 1. Gerardo's language skills are something that makes him unique, something that distinguishes him from most people.