Physics section bank #5

http://imgur.com/a/tsDYV

Hi I understand this problem but I was wondering how you are supposed to know to calculate the work using the 266nm laser? Do you just calculate both and find an answer choice that is one of them? (additionally how did they get 2.4 kj for the 325nm laser doesn't 2.2*2=4.4?...did i calculate that wrong?)