Final answer:
Marketo does not de-dupe on email addresses for untrusted list imports.
Step-by-step explanation:
The correct answer is C. Untrusted list imports. Marketo does not de-dupe on email addresses for untrusted list imports. De-duplication is the process of identifying and removing duplicate records from a database. In this case, Marketo does not remove duplicates for untrusted list imports, meaning that multiple leads with the same email address can exist in the system.