The airport was declared " closed " and we had to sit for 1.5 hours inside the plane . Apparently its related to trade union issues . Off we got , happy to arrive in the US of A and given we were the first plane to disembark rushed to passport control to avoid long lines of irritated passengers detained in other flights due to the storm . David joined the US citizen line and quickly went by , while Vero and Marcos slowly reached the customs officer in the " rest of states " line . Problem Number 1 : when we handed over our passport and customs slip to the officer he requested a green visa slip .

Question: Why did the officer request the visa slip ?
Answer: The trade union issues required visas to be displayed .It is just standard protocol for every passenger of the plane .Because he required payment for the flight we just took .None of the above choices .