On August 8, 2016, Sam, single, age 62, sold for $210,000 his principal residence, which he has lived in for 10 years, and which had an adjusted basis of $60,000. On November 1, 2016, he purchased a new residence for $80,000. For 2016, Sam should recognize a gain on the sale of his residence of: 

a. $50,000 

b. $25,000 

c. $0 

d. $130,000 

e. None of these choices are correct.