Cathy Drake is a social worker on the staff of Veteran Family Center, a voluntary welfare organization. She earns $$42,000$ annually for a normal workload of $2,000$ hours. During $2017$ she contributed an additional $800$ hours of her time to Veteran Family Center at no extra charge. How much should Veteran Family Center record in $2017$ as contributed service expense?

$$0$

$$1,680$

$$8,400$

$$16,800$