For the following scenario, determine the dollar amount of the book$-$tax difference $($if any$)$ written as a positive number in $2016$

On January $1,2015,$ Landmark Corporation offered its CFO $2,500$ options to purchase the company's at the same price offered by the public market on that day, $$12/$share$,$ at any date in the future after the CFO vests. The CFO will vest $25\%$ of its options in $2015,25\%$ in $2016,$ and vest the remaining portion in $2017.$ The CFO promptly exercised all of his options on December $31,2017$ when he was $100\%$ vested and turned around and sold all the shares for $$15/$share on the public market. Assume that on the grant date, Landmark Corporation estimated the value of the options would be $$4/$share$.$ The company uses a calendar year tax period.

a$.$ The book$-$tax difference in $2016$ is $$10,000.$

b$.$The book$-$tax difference in $2016$ is $$2,500.$

c$.$None of the answers given here.

d$.$The book$-$tax difference in $2016$ is $5,000.$

e$.$The book$-$tax difference in $2016$ is $$0.$

a$.$ Temporary

b$.$ permanent

c$.$ not applicable as there is no book tax difference

a$.$ unfavorable

b$.$ favorable

c$.$ not applicable as there is no book tax difference.