Match List-I with List-II:

List-I (Theory proposed)	List-II (Author / Formula)
A. Textural triangle	(I) Sorenson
B. Ideal gas	(II) Schofield
C. pH	(III) Whitney
D. pF	(IV) PV = nRT

Choose the correct answer from the options given below:
(a) [a]-(I), [b]-(II), [c]-(III), [d]-(IV)
(b) [a]-(I), [b]-(III), [c]-(II), [d]-(IV)
(c) [a]-(I), [b]-(II), [c]-(IV), [d]-(III)
(d) [a]-(III), [b]-(IV), [c]-(I), [d]-(II)

Correct option is D

Correct matching: Option (d)
[a]-(III), [b]-(IV), [c]-(I), [d]-(II)
Explanation of correct pairs:
· (a) Textural triangle → Whitney (III)
· Whitney developed the soil textural triangle.
· Used to classify soils based on sand, silt, and clay percentages.
· (b) Ideal gas → PV = nRT (IV)
· The ideal gas equation relates pressure, volume, temperature, and moles of gas.
· Widely used in physical chemistry and physics.
· (c) pH → Sorenson (I)
· S.P.L. Sørensen introduced the pH scale.
· Measures hydrogen ion concentration of solutions.
· (d) pF → Schofield (II)
· Schofield proposed the pF concept.
· pF represents the logarithm of soil water suction (cm of water).
➡️ Hence, option (d) is the correct answer as given in the image.
❌ Why other options are incorrect
· Options (a), (b), and (c):
· Incorrect pairing of authors with theories.
· pH and pF concepts are wrongly interchanged.
· Ideal gas law is not linked with any scientist name here but with its formula.
�� Key Points to Remember
· Whitney → Soil textural triangle
· PV = nRT → Ideal gas equation
· Sorenson → pH scale
· Schofield → pF (soil moisture tension)