Earth Dynamics – Modern plate tectonics\nWhich statement(s) correctly describe the modern theory of plate tectonics and seafloor dynamics?

Introduction / Context:
Plate tectonics integrates continental drift and seafloor spreading into a single framework. Lithospheric plates move over the asthenosphere, creating, transporting, and recycling oceanic crust while reshaping continents and ocean basins.

Given Data / Assumptions:

• (a) addresses seafloor creation and continental motion.
• (b) attributes ridge volcanism/spreading to convective circulation within the mantle (spelled “convection”).
• (c) describes subduction zones where dense oceanic plates descend beneath lighter continental (or oceanic) plates.

Concept / Approach:
All three statements are essential elements of plate tectonics: seafloor spreading at mid-ocean ridges, plate motion driven in part by mantle convection (plus slab pull and ridge push), and destruction/recycling of oceanic crust at subduction zones. Hence the comprehensive answer includes all.

Step-by-Step Solution:
Confirm creation: new basaltic crust forms at ridges.Confirm motion: continents ride on plates that drift relative to one another.Confirm destruction: old oceanic crust is consumed at trenches via subduction.Therefore choose “All of the above”.

Verification / Alternative check:
Age of oceanic crust increases away from ridges and is youngest at ridge axes; deep earthquakes and trenches mark subduction—observations consistent with all statements.

Why Other Options Are Wrong:
Each single statement is correct but incomplete. The theory requires the full cycle: creation, motion, and destruction.

Common Pitfalls:
Focusing only on continental drift and forgetting seafloor recycling; or thinking continents plow through oceanic crust without plate interactions.

Final Answer:
All of the above