Consider the following information for YumYum Inc. as of December 31, 2015:

YumYum has a service contract with a maintenance company. The contract is for cleaning services at a rate of $3,000 per month. The maintenance company bills YumYum semiannually on October 1 and April 1. The contract commenced on October 1, 2015. During 2015, YumYum received advances from customers for the first time. Total collections in 2015 were $100,000. At December 31, 2015, $30,000 of the advances had not been earned. In 2015, YumYum had 50 employees. Each employee earned 10 days of vacation pay. The actual rate for 2005 was $300 per day. During 2015, 10 employees used all of their vacation days for 2015. At January 1, 2015, the Vacation Payable account had a balance of $10,000.

Required:

What is the amount of liability for advances from customers at December 31, 2015?

a. $30,000

b. $70,000

c. $100,000

d. $130,000