How Does the Strength of Continental Crust Vary with Depth

Multiple Choice

How does the strength of continental crust vary with depth?

A) Rocks become stronger with depth and then get weaker deep in the crust.
B) Rocks weaken with depth and then get stronger deep in the crust.
C) Rocks systematically get stronger from the surface to deep in the crust.
D) Rocks systematically get weaker from the surface to deep in the crust.