With what theory do scientists explain the formation of our world's landforms?
a.
theory of supercontinent drift
b.
theory of land mass glide
c.
theory of plate tectonics
d.
theory of crustal rotation

c.  theory of plate tectonics

Explanation:

The plate tectonic theory was made to shows the relation of the continent on the world and they're associated with the oceanic water masses and thus scientist could explain the formation if the seabed and the formation of the different layers of the earth and also help evaluate the formation of the surface of the earth and their relation to the various landforms that are found across the world till date. Startin with the arrangement of the plates i.e the convection, divergent and the transform plate zone switch then form the basis of the collision and the transformation of the rocky landmass of the planet.

The sun's parallax would be 180 degrees, greater than which you can't get.  so a. would be your anwser