The correct answer is - twice.
John Smith was held as prisoner twice during his life. The first time he had been captured and held as prisoner by the Ottoman Turks, while the second time he was kept as prisoner by a Native American (Indian) tribe, and he was able to escape with the help of a girl named Pocahontas (allegedly).
Considering his life, it is even weird that he has only been captured and held as prisoner so few times. He was a man that loved traveling and was an explorer, and a soldier, so he was getting himself in a very dangerous positions more often than not. He was also a colonial governor of the Jamestown colony, as well as Admiral of New England. Smith also is regarded as an author, though his credibility from historic point of view is very often disputed.