Step 1: Evaluating Statement A.
The lithosphere, the Earth's rigid outer layer (crust and upper mantle), typically ranges from 50-200 km thick, with an average of 100 km. Statement A is confirmed as accurate.
Step 2: Evaluating Statement B.
The average densities are: continental crust (~2.7 g/cc), oceanic crust (~3.0 g/cc), and the rigid mantle (~3.3 g/cc). A combined lithosphere density would be approximately 3.1-3.2 g/cc. A value of 3.6 g/cc is too high, matching the underlying asthenosphere. Statement B is determined to be inaccurate.
Step 3: Evaluating Statement C.
Continental crust is primarily silicon and aluminum ("SiAl"), while oceanic crust is mainly silicon and magnesium ("SiMa"). Because the lithosphere encompasses both, the statement is not universally applicable.
Step 4: Evaluating Statement D.
Basalt dominates the oceanic crust, which covers around 70% of Earth's surface. Although continental crust is largely granitic, basalt is a significant component of the entire lithosphere's crust. Statement D is considered accurate regarding the most prevalent rock type.
Conclusion: Statements A and D are the most accurate. Therefore, the answer is "A and D only".