try as i _______ , i couldn't turn the key

hiya stu! howdy cowboy :P

a)could b)would c)might d) should and why? tnx \o/

ps: btw you didn't answer this question shame on you :/ : It was the collapse of the dotcom boom that finally did ___ him? a) with b) out c) for d) about and why? + meaning of the last sentence please! kill ya :/