The difference between Paciolis accounting system and other systems that existed at his time:

A. his system is the first that was directed toward accountants his system is the only one that required merchants to keep two different sets of books

b. his system is the only one that could be used across borders in the late 15th century

c. his system is the only one that employed double-entry bookkeeping

d. his system is the only one that required merchants to eat pizza while making entries