Question

(A) Majority of red soils are loams with values of pH ranging between 5.0 to 8.0.
(B) Laterite soils which are generally acidic have an average pH range between 6.0 to 7.0.
(C) Red and yellow soils have a pH around neutrality or else slightly on the acidic side.
(D) Desert soils have fairly high pH and varying amounts of calcium carbonate.
(E) The alkali soils have a high pH which may range between 7.0 and 8.0.
Choose the correct answer from the options given below:

• A. (A), (C) and (D) only.
• B. (A), (B) and (C) only.
• C. (C), (D) and (E) only.
• D. (B), (C) and (D) only.

Hint:

Rank the soils by how strongly leached or calcareous they are, from laterite (most acidic) to alkali soils (most alkaline).

Answer 1

The Correct Option is A

Rank the soil types from most acidic to most alkaline and see which stated ranges fit.
Laterite soils sit at the acidic extreme because of intense leaching of bases, roughly pH 4 to 6, so calling them 6.0 to 7.0 pushes them too close to neutral, making (B) false.
Red and yellow soils sit just above laterites, close to neutral or mildly acidic, which matches (C), so it is true.
Red soils overall, being loamy and less leached than laterites, cover a wider band from mildly acidic to mildly alkaline, about 5.0 to 8.0, matching (A), so it is true.
Desert soils sit at the alkaline end because of calcium carbonate accumulation under low rainfall, matching (D), so it is true.
Alkali (sodic) soils sit at the extreme alkaline end, with pH commonly above 8.5 and sometimes near 10; capping them at 7.0 to 8.0 badly understates this, so (E) is false.
\[\boxed{\text{(A), (C) and (D) only, option 1}}\]