On January 1, 2021, Riverbed Inc. granted stock options to officers and key employees for the purchase of 18,000 shares of the company's $10 par common stock at $23 per share. The options were exercisable within a 5-year period beginning January 1, 2023, by grantees still in the employ of the company, and expiring December 31, 2027. The service period for this award is 2 years. Assume that the fair value option-pricing model determines total compensation expense to be $343,400. On April 1, 2022, 1,800 options were terminated when the employees resigned from the company. The market price of the common stock was $36 per share on this date. On March 31, 2023, 10,800 options were exercised when the market price of the common stock was $41 per share. Prepare journal entries to record issuance of the stock options, termination of the stock options, exercise of the stock options, and charges to compensation expense, for the years ended December 31, 2021, 2022, and 2023. (Credit account titles are automatically indented when 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.) Date Account Titles and Explanation Debit Credit