Explanation:

Let’s break down what the function of a legal institution is in society and what each of those options really means:

- Integration: Legal institutions tie people together by creating common rules and standards. When laws are clear and consistently applied, people know what’s expected, so society works better.

- Adaptation: This is really about how groups adjust to change. Legal systems do adapt, but that’s more of a side effect—not the main job.

- Pattern maintenance: This means keeping values and norms steady. While laws can reinforce values, it’s more about keeping peace and order.

- Goal attainment: This is reaching shared objectives. Legal institutions help, sure, but they're not the goal-setters—they enforce the goals set by others.

So, the correct answer is:

Option: 1 - Integration

What this really means is that legal systems pull everyone together, make society feel more stable and fair, and give people a shared sense of how things should work. That’s integration in action. The other options? They matter, but they don’t hit the main point.