Thermal metamorphism progresses in a sequence from **lower-grade facies** to **higher-grade facies** as temperature increases. The correct sequence based on increasing metamorphic grade is:
The correct order of thermal metamorphism facies is:
\[ \mathbf{Albite\text{-}epidote\ hornfels \rightarrow Hornblende\ hornfels \rightarrow Pyroxene\ hornfels \rightarrow Sanidinite} \]
Thus, the correct option is: (D).
| Group I | Group II |
| P. Stylolite | 1. Liquefaction |
| Q. Pseudonodule | 2. Diagenesis |
| R. Current crescent | 3. Organo-sedimentary binding |
| S. Stromatolite | 4. Scouring |