challenge: Where is the main beach of Praia de Odeceixe situated?
  
  A. In the small village of Praia de Odeceixe
  B. On the northern side of the Rio de Seixe, sheltered by steep cliffs
  C. On the western coast of the Algarve
  D. At the mouth of the Rio de Seixe (River Seixe), on the border between the Algarve and the Alentejo
  Answer: 