Explanation:

- Option 1: Contradiction

- This means a direct disagreement or inconsistency between ideas or statements. It is not specific to generations.

- Option 2: Generation gap

- Correct Answer: This refers to differences in attitudes, values, and behaviors between younger and older generations, often leading to mutual opposition and misunderstanding.

- Option 3: Social distance

- Means the level of acceptance individuals or groups have towards others. It’s more about social relationships in general, not specifically about age or generation.

- Option 4: Conflict

- This is a broad term for any kind of disagreement or struggle, not only among generations.