What is affected when you change the default locale for an organization?

Taking each of the question´s options in turn, an organization will not be affected by a change of language because each user can select the language of his choice without changing any of the other content. The time zone is also something a user can select while other data types remain the same. This is also true of currency settings. However, it is crucial for the user to set these back again after individual use.

With respect to the date fields, if the default locale is altered these will change, as will the currency settings and several others too. So the correct answer to this question is A - date fields. These are the ones changed when the default locale is changed.