Hmm... let me analyse this...
If the hat was for sun protection obviously (a). (b) would just be impractical.
However, if Togruta have some sort of equivalent to Santa hats/ Party hats (or a hat worn for decoration not practicality) in their culture, then I'd say (b). But, unless we get a explanation, it could go either way.
. . .
(I'm probably waaaay overthinking this.)