For what reform is Justinian BEST remembered?

Question

A. he healed the schism between the roman and byzantine churches by conquering constantinople during the crusades
B. he pioneered the use of bank checks so that his subjects could have access to money wherever they were
C. he influenced the roman catholic church and midiecal monarchs, who modeled their laws on the principles of his code
D. he encouraged his subjects to improve their social class through scholatic and military achievements
My answer is C ?