In 2012, Hu Corporation Granted Incentive Stock Options to Trevor

In 2012, Hu Corporation granted incentive stock options to Trevor to buy 5,000 shares of Hu stock at $20 per share exercisable for six years. At the date of grant, the stock was selling for $19 per share. In 2015, Trevor exercises the options when the market price was $38 per share. Trevor sells the stock in 2017 for $42 per share. How much income or gain does Trevor recognize and in which year?

A) $110,000 capital gain in 2017 only
B) $95,000 income in 2012 only
C) $90,000 income in 2015 and $20,000 capital gain in 2017
D) $90,000 income in 2015 only