There is no right answer to this pop quiz. I'm merely taking a survey.

You have to live one year in the life of another being. You are guaranteed that you won't die during this experience and that you can travel freely wherever such a creature could travel. Which ONE of the following four do you choose?

A. The opposite sex
B. An identical twin
C. An underwater creature of your choice
D. A flying creature of your choice

Please indicate which one you choose in the comments and then, please comment if there is something else you'd like to be for a year, what is it?

Thanks to responders.