Scientists are currently trying to determine the extent to which tectonic plates have been shifted from their previous positions by earthquakes and other similar phenomena.
A) to which tectonic plates have been shifted
B)to which tectonic plates have shifted
C)of the shift of tectonic plates
D)to tectonic plate shifting
E)that tectonic plates have been shifted

Please tell when have been and when have should be used.

Thanks!!