I'm looking for some clarification on what happens when a character has multiple weapons equipped.

During an attack it seems very obvious that the character can only use bonuses and abilities on the weapon that they are attacking with.
However, what happens if the weapon/gear provides a defensive bonus (i.e. the [crowns] = [hats] ability of Elizabeth Sparkle's Meka Fists)?

a) does the character get all defensive bonuses from all equipped weapons/gear?
b) does the character only get the defensive bonus on the last used weapon/gear?