Preimer Life Company is a life insurance company that collects, stores, prepares and provides customized life insurance policy to customers in the Midwest. When a customer's information is received, it is recorded in a database and a ticket is provided to the policy underwriter. When the life insurance policy is issued, the database is updated so that it always reflects the correct amount of life insurance coverage and the length of the policy available to the customers. In a data flow diagram, which type of symbol would be used to represent policy underwriters?
a. a square.
b. a circle.
c. double lines.
d. an arrow.