Tectonic plate movement is run by convection of mantle currents.
An “isogloss” is a geographic boundary of a linguistic feature.
“Centum-Satem” is the Indo-European language family. Centum includes Germanic, Celtic, and Italic. Satem includes Iranian and Balto-Slavic.
Greek, Sanskrit, French, German, English and other Indo and European languages share commonalities and are thought to be derived from these earlier parent languages.
I think it B or D sorry if wrong
The answer would be b) push factors
