In Hamdi v$.$ Rumsfeld, the president....

a$)$ has no authority to declare someone an enemy combatant.

b$)$ can only declare someone an enemy combatant if he receives approval from a majority of the Senate Intelligence Committee.

$$ c$)$ can only declare someone an enemy combatant if he receives approval from the Foreign Intelligence Surveillance Court.

$$ d$)$ has the unilateral power to declare someone an enemy combatant.