On October $15,2020,$ the board of directors of ABC Corporation approved a stock option plan for key executives. On January $1,2021,20$ million stock options were granted, exercisable for $20$ million shares of Ensors $$1$ par common stock. The options are exercisable between January $1,2024,$ and December $31,2026,$ at $80\%$ of the quoted market price on January $1,2021,$ which was $$15.$ The fair value of the $20$ million options, estimated by an appropriate option pricing model, is $$6$ per option. Ensor chooses the option to recognize forfeitures only when they occur.Ten percent $(2$ million$)$ of the options were forfeited when an executive resigned in $2022.$ All other options were exercised on July $12,2025,$ when the stocks price jumped unexpectedly to $$19$ per share.Required:$1.$When is ABCs stock option measurement date?$2.$Determine the compensation expense for the stock option plan in $2021.($Ignore taxes.$)3.$Prepare the journal entries to reflect the effect of forfeiture of the stock options on Ensors financial statements for $2022$ and $2023\mathrm{.}4.$Is this effect consistent with the general approach for accounting for changes in estimates? Explain$\mathrm{.}5.$Prepare the journal entry to account for the exercise of the options in $2025.$