During 2015, Al made the following charitable contributions:

Cash $20,000

Stock in Thrush Corporation (is publicly traded corporation) $30,000

The stock in Thrush Corporation was acquired as an investment three years ago at a cost of $10,000. Als AGI for 2015 is $70,000. What is Als charitable contribution carryover for 2015 to 2016? (THE CORRECT ANSWER IS B, BUT WHY)

a. $30,000

b. $15,000

c. $35,000

d. $21,000

e. None of the above