Answer:
B They move because of the convection currents in the mantle.
CO2 and NaCl are both compounds
I'm really sorry but I am not from India.
Contrary to popular belief the scientific method is an iterative process because scientists often have to revisit, repeat or revise previous steps. It is very common for an experiment to be done many times in different international laboratories in order to confirm that a conclusion is valid. All good scientific experiments should allow results to be replicated.
Wheres the diagram
We have to see the diagram to answer your question