Which of the following is NOT a network flow model?

Saunders purchased a home from Barnes and agreed to assume an existing conventional loan. The lender agreed to the assumption and issued a substitution of liability. Under these circumstances:

A: Saunders is primarily responsible for the loan and Barnes remains liable as a surety; B: Nothing is being accomplished if the loan is secured by a purchase-money deed of trust; C: Barnes is relieved from further duties under the obligation; D: Barnes remains primarily responsible for the loan and Saunders is secondarily liable.

Virtually every company should have a "service department."

Indicate whether the statement is true or false