Choose the word 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 heart of Ha Noi. Legend has it that in the mid-15th century, Heaven gave Emperor Le Thai To (Le Loi) a magical sword ___(1)___ he used to fight against the Chinese, the Ming aggressors, out of Viet Nam. After that one day when he was out sailing in the lake, a giant ___(2)___ 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) ___(3)___ it is believed the sword was taken to its original divine owners. The tiny Tortoise Pagoda, topped with a red star, is ___(4)___ a small island in the middle of the lake; it is often used as an emblem of Ha Noi. Every morning around 6 a.m., local residents can be seen around Hoan Kiem Lake ___(5)___ their morning exercise, jogging or playing badminton.