Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage.

Hoan Kiem Lake is an attractive body of water right in the (1) ___________ of Ha Noi. Legend has it that in the mid-15^th (2) ________ , Heaven gave Emperor Le Thai To (Le Loi) a magical sword which he used to fight (3) ________ the Chinese, the Ming aggressors, out of Viet Nam. After that one day when he was out (4) ________ in the lake, a giant (5) ________ tortoise suddenly grabbed the sword and disappeared into the depths of the lake. Since then,the lake has been known as Hoan Kiem Lake (Lake of the Restored Sword) because it.

(1) _________

• A. 
  middle
• B. 
  main
• C. 
  heart
• D. 
  point