Mark received 10 ISOs (each option gives him the right to purchase 16 shares of Hendricks Corporation stock for $6 per share) at the time he started working for Hendricks Corporation five years ago, when Hendricks's stock price was $5 per share. Now that Hendricks's share price is $35 per share, Mark intends to exercise all of his options and hold all of his shares for more than one year. Assume that more than a year after exercise, Mark sells the stock for $35 a share.

a. What are Mark's taxes due on the grant date, the exercise date, and the date he