Many US ships do have anti-missile systems. It would need to be the right kind of ships obviously, carriers can perform this obvious, aegis cruisers are specialized at it so they can as well. And enough or the right kind of missiles can get through much of the time.
It will be really interesting to see if Iran can make good on its threats in a sustained way. If they can the US is in a pretty bad spot in a lot of ways. Still I expect the US will goad a couple of ships to try, if even some ships get through Trump will be leaning heavily on those countries to keep the ships running even if they're taking losses. At a certain point the countries will likely get a spine and explain ship replacement lead times are too much and they have to stop sending them because if they don't they'll be stuck with inadequate shipping capacity for years after this conflict. At that point we really enter the cool zone.
but options 2 and 3 spell very, very, very dire times for those in the imperial core as it's a very orderly managed decline that's liable to be able to potentially draw it out many more decades into the future and inflict incredible amounts of suffering on those of us stuck here in the mean-time (beyond just treats being more expensive).
How long until the US navy just starts hijacking these tankers out of Iranian range and redirecting them to the west because they can't otherwise break the blockade? Trump will make a big show of saying he's paying the Chinese for the oil so they're not losing anything and it's totally not piracy.