The Medici bank differed from other banks in one very important way, and the chance of a large borrower defaulting did not pose a significant risk. The Medici bank was:

a. Diversified and made up of interlocking relationships dependent on the rest
b. Centralized, and made up of interlocking relationships, each dependent on the rest
c. Centralized, and lent to people that were related
d. Diversified, and made up of interlocking partnerships, each independent from the rest