Context: My stepmother was limping for the rest of the day , unfortunately , and she avoided walking more than necessary . The Stonehenge replica was so - so ; it was made of concrete , so it looked a bit silly . Still , it was mildly amusing to see .

Question: why was the Stonehence monument made of concrete ?
Options:
0. They could not have the real thing
1. Polystyrene is not very durable
2. Stonhence was not made of wood
3. None of the above choices .
Answer: 0