An app builder needs to change the data types of a few 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 additional steps in order to retain existing functionality?
a. changing the datatype of a field used in a report from text to an encrypted field.
b. as an external id from number to text.
c. in an apex class from number to text.
d. in lead conversion from number to text