Please help on the below. Thank you

Carson is an employee of XYZ Corporation. XYZ granted Carson an incentive stock option on January $1,2020.$ The option gave him the right to purchase $1,000$ shares of XYZ for $$5,000,$ which was the fair market value of the stock at the time the option was granted. Carson exercised his option on February $15,2022,$ when the fair market value of the stock was $$11,000.$ He did not sell or dispose of the stock that year.

When Carson files his $2022$ return, what amount should be reported as an excess of AMT income over regular tax income on Form $6251,$Alternative Minimum Tax $-$ Individuals?

a$.$$$0$

$$b$.$ $$5,000$

$$c$.$ $$6,000$

d$.$$$11,000$