Read the passage and answer the questions given below it.
After Cyclone Sidr struck Bangladesh in November 2007, those who surveyed the damage noticed something odd. The worst-hit villages were not always those with the weakest houses. They were often those with nothing between them and the sea. Where the Sundarbans, the largest mangrove forest in the world, stood in the way, the water had arrived tired.
How a forest does this is less dramatic than the word ‘shield’ suggests. A mangrove does not block a storm surge, the hump of seawater a cyclone pushes ahead of it. It slows it down. Stilt roots arch out of the mud like the legs of a crouching insect, and thin breathing roots poke up in their thousands. Water forced through this tangle loses a little of its strength with every metre. The forest levies a toll on the water, and the toll is paid again and again. The surge that reaches the landward edge is lower and slower.
That is also the catch. The toll depends on distance. A belt of trees several kilometres deep can take the sting out of a surge. A thin fringe, the kind left when the rest is cleared for paddy fields or prawn ponds, does far less. Such a fringe looks green from a boat, which is why it is easy to be sanguine about it. When Cyclone Aila came in 2009, long stretches of the mud embankments around the islands gave way, and salt water lay on the fields for more than one season.
None of this makes the mangroves less valuable. It makes them harder to protect. An embankment can be raised in one dry season. A forest doing the same work takes decades to grow, and works only if it is left wide and whole.
Which of the following best expresses the central argument of the passage?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Mangroves weaken a storm surge rather than stop it, and the protection they give lasts only while the forest is kept wide and whole.
The passage explains how the mangroves protect the coast and why that protection is easy to lose.
- A mangrove “does not block a storm surge”. It slows it. A storm surge is the hump of seawater a cyclone pushes ahead of it.
- The water loses some strength with every metre. So the protection “depends on distance”. A deep belt helps. A thin fringe does far less.
- The last line says the forest works “only if it is left wide and whole”. This is the writer’s main point.
Why the Other Options are Incorrect?
Option 1: The Sundarbans saved Bangladesh from Cyclone Sidr, which proves that forests should now replace embankments along the coast. — Incorrect. Overstated: The forest only made the water arrive “tired” in some places. The writer never says forests should replace embankments.
Option 2: Clearing mangroves for paddy fields and prawn ponds was the main reason why Cyclone Aila broke the embankments. — Incorrect. Wrong link: The passage mentions both the clearing and the broken embankments. But it does not say that one caused the other.
Option 3: Calling the mangroves a ‘shield’ is misleading, since the forest does little to lessen the harm a cyclone causes. — Incorrect. Contradicted: The writer says the word is only “less dramatic” than the truth. A deep belt can “take the sting out of a surge”, so the forest does real good.