The pirate Blackbeard A had a short black beard. B was of medium height. C was a frightening man. D had ships all over the Caribbean.

Based on the text provided, it does not explicitly state that Blackbeard had a short black beard, was of medium height, or had ships all over the Caribbean. However, the text does describe him as having a reputation as a dangerous pirate, and his life came to an end in a battle, implying he was a figure that commanded fear and authority.

While the text doesn't directly answer these specific descriptive points, the overall narrative of his actions and demise aligns with the image of a formidable pirate. Without further information directly from the text about his physical appearance or the extent of his fleet's reach beyond capturing 50 ships, it is impossible to definitively select an answer from the given options based solely on the provided passage.