a) 好! Excellent! / that would be nice! (confirmation)
When you shout "好!" it means exactly as "Excellent!"
"好!" also means to approve others' idea.
b) 好啊!OK (confirmation)
hao3a5 / hao3a1:
When your friend asked you if you want to have a walk, you would respond with "好啊!"
hao3a4
Used in ironic way: Look what you have done! / Let's see what's next(fake approve)
c) 好的!Yes (confirmation on assignment)
When your boss ask you to prepare for a presentation, and you would probably answer "好的".
d) 好吧!all right (confirmation because you have to)
Your mom asked you to do some housework before you can play computer games, after failing begging her, you answered "好吧"
e) 好了!