Imperial Construction Inc. $($IC$)$ issued $1,000$ nonqualified stock options $($NQOs$)$ to its employees on January $1,2020,$ with an estimated value of $$5$ per option. The options vest $($accrue$)$ for four years $($beginning in $2020).$ Each option allows the holder to purchase one share of stock at $$10.$ On January $1,2024,$ employees exercised $1,000$ options as IC's stock price reached $$15.$ What is the amount of the booktax difference in $2024$ associated with the stock options? Is it favorable or unfavorable? Is it temporary or permanent?