Read the following announcement and mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 13 to 16.

SAPA TREKKING TOUR, VIET NAM
* A three-day walk of 20 kilometres a day through the mountains (13) ______ the north of Viet Nam
* Enjoy some of (14) ______ scenery
* Stay with local people (15) ______ about their culture and (16) ______ local food
* Price: $80/adult (children not allowed)
* Starts every Wednesday and Sunday