• Classification and Mineral Groups of Soil Minerals:
• Hornblende: Complex inosilicate chain silicate belonging to the Primary amphibole silicate group $\rightarrow$ (IV)
• Chlorite: Hydrous aluminosilicate clay belonging to the Secondary 2:1:1 silicate clay group $\rightarrow$ (I)
• Goethite ($\alpha\text{-FeOOH}$): Crystalline iron oxyhydroxide belonging to the Secondary non-silicate sesquioxide group $\rightarrow$ (II)
• Anorthite ($\text{CaAl}_2\text{Si}_2\text{O}_8$): Calcium endmember of plagioclase, classified under the Primary tectosilicate feldspar group $\rightarrow$ (III)
• Systematic Match: (A)-(IV), (B)-(I), (C)-(II), (D)-(III) corresponds to Option 4.

Correct option: (4) (A) - (IV), (B) - (), (C)- (I), (DB) - (tll)

• Geochemical Mobility Series in Soils (Polynov & Perelman): Elements exhibit distinct relative mobilities during weathering based on ionic potential and solubility:
• Highly mobile anions: Sulfate ($SO_4^{2-}$) and chloride ($Cl^-$) migrate rapidly with gravitational drainage water.
• Mobile alkaline earth cations: Calcium ($Ca^{2+}$) is readily displaced and leached before potassium.
• Weakly mobile cations: Potassium ($K^+$) is retained and fixed in the interlayers of 2:1 illitic clays.
• Immobile sesquioxides: Alumina ($Al_2O_3$) and iron oxides are practically insoluble under normal soil pH and accumulate in the profile.
• Mobility Sequence: $SO_4^{2-} \gt Ca \gt K \gt Al_2O_3$. (Correct answer: Option 2)

• Definitions:
• Volume of soil solids = $V_s$
• Volume of soil pores = $V_f$
• Total soil volume = $V_t = V_s + V_f$
• Porosity ($f$) = $\frac{V_f}{V_t} = \frac{V_f}{V_s + V_f}$
• Void ratio ($e$) = $\frac{V_f}{V_s}$
• Derivation:
• Dividing the numerator and denominator of $f$ by $V_s$:

• Conversely, $e = \frac{f}{1 - f}$.
• Conclusion: The relationship $f = \frac{e}{1 + e}$ is correct. (Correct answer: Option 4)