Some things to take into consideration... How often are these classes offered? Are they offered every semester? Or maybe once in a great while? Also take into consideration what year you are (or, more importantly, how many credits you have left until you graduate). I'd look at those things before making a decision. If all three courses are offered frequently, then I'd probably take the easier one to balance out the other two. If one of the classes is only offered once every three years or something, I'd probably take that one. Also, if you're early in your college career, you will always have more time for classes in the future (and don't forget, one of those might even be offered in the summer!). Don't take on too much and burn yourself out. And, sure, while having the Aging and Society class on your resume might be good for you in the future, can it afford to wait for a semester or two?

Hope that helps a little! Good luck this semester!