Explanation:

Let’s break it down:

- Option 1: Co-operation

This is definitely a big part of social relationships—people working together, helping each other out, and sharing goals.

- Option 2: Conflict

Conflict also comes up a lot in social relationships. It’s not always about getting along; disagreements are natural.

- Option 3: Co-operation and conflict

What this really means is, social relationships include both sides—people cooperate, but sometimes they clash too. It’s not just one or the other.

- Option 4: Face to face contact

That was important in earlier definitions, but now social relationships can also exist online, not just face-to-face.

So, the correct answer is Option 3: Co-operation and conflict.