Citron Inc., a publicly accountable company, has an employee stock option plan (ESOP) for several senior executives. The plan was granted on January 1, 20X5, for a total of 20,000 options for one share each. The options have an exercise price of $25 per share. The options have a vesting period of two years from the grant date. 100 % of the options have vested. Details of the stock option plan are as follows:

The fair value of the ESOP using an appropriate option-pricing model, such as Black Scholes, is $300,000 on the grant date.

On April 1, 20X7, 7,000 options were exercised. The market price of Citron's shares on this date was $31.

On August 1, 20X8, 10,500 options were exercised. The market price of Citron's shares on this date was $33.

On December 31, 20X9, the remaining options were not exercised and expired. The market price of Citron's shares on this date was $34.

What is the amount Citron should record for common shares when the options are exercised on April 1, 20X7?

a) $105,000 b) $175,000 c) $217,000 d) $280,000