Which alternative is correct?

1. The children own a cat. It is …
   • the children’s cat.
   • the childrens’ cat.

2. The man owns a car. It is …
   • the man’s car.
   • the mans’ car.

3. Martin owns a cabin. It is …
   • Martin’s cabin.
   • Martins cabin.

4. The women own a shop. It is …
   • the womens’ shop.
   • the women’s shop.

5. Mathias owns a farm. It is …
   • Mathias’ farm.
   • Mathia’s farm.