richard and alice are divorced and under the terms of their written divorce agreement signed on december 30, 2008, richard was required to pay alice $1500 per month of which $600 was designated as child support. he made 12 such payments in 2015. additionally, richard voluntarily paid alice $1200 per month for 12 months of 2015, no portion of which was designated as child support. assuming that alice has no other income, her tax return for 2015 should show gross income of:

a. $0

b. $9600

c. $10800

d. $18000

e. none of the above