Which data type change will require the app builder to perform the additional steps in order to retain existing functionalities?

The app builder needs to change the data types of new custom fields. The app builder is not able to delete and recreate any of the fields, nor modify any apex code.

Which data type change will require the app builder to perform the additional steps in order to retain existing functionalities?
A . Changing the data type of a field used in an apex class from number to text.
B . Changing the data type of a field used in a report from a text to an encrypted field
C . Changing the data type of a field used as an external id from number to text.
D . Changing the data type of a field used in lead conversion from number to text

View Answer

Answer: C

Explanation:

If you change the data type of any custom field that is used for lead conversion, that lead field mapping will be deleted. If you change the data type of a custom field that is set as an external ID, choosing a data type other than text, number, or email will cause the field to no longer act as an external ID.

The option to change the data type of a custom field is not available for all data types. For example, existing custom fields cannot be converted into encrypted fields nor can encrypted fields be converted into another data type. https://help.salesforce.com/apex/HTViewHelpDoc?id=notes_on_changing_custom_field_ty pes. htm&language=en