@Red5 The quiz has neglected to include "Mx", for those (generally non-binary or gender-fluid) who don't identify with the other four titles. I think it's important that learners understand that, especially if they're dealing with UK businesses, they will come across that title.
As an aside, though connected, they should also be aware that in most public organisations these days, someone's email signature line will include their preferred pronoun (he/she/they). The reader will need to use that information to determine the relevant honorific.
