Today, the annual rate of tectonic plates movement is observed and measured by satellites.
So, the answer is option A. Satellites.
~Hope this helps!
Continental Rifts are called Continental Plate or Divergent Boundary or Convergent Boundary or Continental Drift.
Hoped I helped:D
B) Milk- dairy products are Domestic milk markets were heavily regulated until the 1980s, particularly for milk used for domestic fresh milk sales. ... Growth in the Australian dairy industry is dependent on expanding export markets.