On January 1, 2018, Pronghorn Property Management Inc. introduced a stock-based compensation plan for its senior executives. The company has a December 31, 2018 year-end and the following events occurred: January 1, 2018 - The company issued 324,000 options to senior management executives for the purchase of shares at $11/ share. The fair value of the options using an options pricing model is $2,268,000. Options vest over a three-year period and it is estimated that 90% of the options will vest. At the end of 2021, any unexercised options will expire. December 31, 2018 - Management now estimates that 85% of the options will vest. December 31, 2019 - Management now estimates that 80% of the options will vest. January 1, 2021 - 108,000 options are exercised when the market price is $15 / share. Record the journal entries associated with the above transactions including any necessary entry at December 31, 2021. (Credit account titles are automatically indented when the amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter O for the amounts.)