Which of the following is an example of a not$-$for$-$profit organization?

a$.$ Wal$-$Mart stores, a retail chain that aims to maximize the difference between its total revenue and total cost

b$.$ The U$.$S$.$ Department of Education, a government agency that coordinates federal assistance for schools in the United States.

c$.$ Fishing$-$Passion, a Seafood Producers Cooperative that helps seafood producers to minimize costs

d$.$ The American Museum of Natural History, an organization that relies on tax$-$deductible memberships and donations for funding