This questions appears in the Marketo Certification Guide http://pages2.marketo.com/rs/561-HYG-937/images/MCE-preparation-guide-2015-FINAL-5-7-15.pdf
6. How many lead records will exist when a person fills out the same Marketo form multiple times with the same email address?
I thought the answer was A. - but if so why do we need to de-duplicate or merge leads?
Bit of a brainteaser? Anyone?