Cell Phones Present a Problem for Pollsters for All of the Following

Cell phones present a problem for pollsters for all of the following reasons EXCEPT

A) cell numbers are not listed in telephone directories.
B) it is illegal to using robopolling to contact cell phone users.
C) cell phone users may be located anywhere.
D) cell phones are more common among younger Americans.
E) most cell users have a landline, thus resulting in being "double polled."