On October $15,2023,$ the board of directors of Martinez Materials Corporation approved a stock option plan for key executives. On

January $1,2024,19$ million stock options were granted, exercisable for $19$ million shares of Martinez's $$1$ par common stock.

The options are exercisable between January $1,2027,$ and December $31,2029,$ at $90\%$ of the quoted market price on January $1,$

$2024,$ which was $$20.$

The fair value of the $19$ million options, estimated by an appropriate option pricing model, is $$6$ per option.

Martinez chooses the option to recognize forfeitures only when they occur.

Ten percent $(1\mathrm{.}9$ million$)$ of the options were forfeited when an executive resigned in $2025.$

All other options were exercised on July $12,2028,$ when the stock's price jumped unexpectedly to $$38$ per share.

Required:

When is Martinez's stock option measurement date?

Determine the compensation expense for the stock option plan in $2024.($Ignore taxes.$)$

Prepare the journal entries to reflect the effect of forfeiture of the stock options on Martinez's financial statements for $2025$ and

Prepare the journal entry to account for the exercise of the options in $2028.$