Question

Assertion A: Sub-surface drainage is long lasting and has lesser maintenance.
Reason R: In surface drainage system weed growth and farm machinery movement interrupts flow.
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both A and R are correct and R is the correct explanation of A
• B. Both A and R are correct but R is NOT the correct explanation of A
• C. A is correct but R is not correct
• D. A is not correct but R is correct

Hint:

Sub-surface drainage: pipes buried underground.
It is long lasting and requires less maintenance.
Surface drainage: open ditches, prone to weed growth and damage.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Sub-surface drainage and surface drainage are two methods of removing excess water.
We need to evaluate the given statements.

Step 2: Key Formula or Approach:
No specific formula.
Need to understand the advantages of sub-surface drainage.

Step 3: Detailed Explanation:
Sub-surface drainage is indeed long lasting and has lesser maintenance.
This is because it is buried underground and not exposed to disturbances.
Surface drainage systems can have weed growth and farm machinery movement that interrupts flow.
This is a correct statement.
However, the reason given (surface drainage problems) is not the explanation for why sub-surface drainage is long lasting and has lesser maintenance.
The reason is that sub-surface drainage is less affected by surface activities.
Thus, both A and R are correct, but R is not the correct explanation of A.

Step 4: Final Answer:
Both A and R are correct, but R is NOT the correct explanation of A.
Hence, the correct option is (B).