When Stacy tries to delete the field "Image,” in the Design view image below, she receives no warning message and the field deletes. But when she attempts to delete "BotanicalOrigin,” a warning message appears. Which best explains this difference?
a. “Image” is a primary key, and “BotanicalOrigin” is not a unique identifier.
b. “Image” is not a unique identifier, but “BotanicalOrigin” is a primary key.
c. “Image” contains no data, but “BotanicalOrigin” does contain data.
d. “Image” contains data, but “BotanicalOrigin” does not contain data.