Final answer:
The flat bottomed Chinese ship with square sails described in the question is known as a 'Junk', a large and sturdy vessel used historically for various purposes including military transport during the Ming Dynasty era.
Step-by-step explanation:
The ship being described in the question is a traditional Chinese sailing vessel known for its robust structure and characteristic square sails, which is option A) Junk. Chinese junks were engineered for long voyages, significant cargo loads, and could vary in size – some were even large enough for military personnel transport as evidenced by the massive treasure ships built in shipyards near Nanking during the Ming Dynasty.
Unlike the Arab dhow with its lateen sails or the European caravel with both square and triangular sails that allowed for tacking into the wind, the Chinese junk had square sails and a flat bottom, designed for stability and capacity rather than speed or maneuverability on the high seas.