Sean on July 8, 2018
I selected C because it said some pollen is linked to multiple areas and therefore it you would not be able to pin point the which specific geographic location.
Is the passage referring to ONLY using pollen that is KNOWN to be unique? At which point C would be irrelevant since this method would not be referring to those types of pollen?
Thanks for help!
Mehran on July 8, 2018