Examine the following statements and select the correct answer using the code given below :
(a) Atolls are ring-shaped islands of coral reefs.
(b) A flat topped submerged volcanic island is known as 'Guyot'.
(c) The average gradient of continental slop in oceans is about 10 degrees.
Code :

Question

Examine the following statements and select the correct answer using the code given below : 
(a) Atolls are ring-shaped islands of coral reefs. 
(b) A flat topped submerged volcanic island is known as 'Guyot'. 
(c) The average gradient of continental slop in oceans is about 10 degrees.
Code :

Accepted Answer

Here's a detailed explanation justifying why Option 4 is the correct answer and why the other options are incorrect:

**Why Option 4: (a) and (b) are correct, is the correct answer:**

*   **(a) Atolls are ring-shaped islands of coral reefs:** This statement is factually correct. Atolls are indeed ring-shaped coral reefs that typically encircle a lagoon. They form when a volcanic island subsides completely beneath the sea, leaving behind a circular coral reef structure.

*   **(b) A flat topped submerged volcanic island is known as 'Guyot':** This statement is also factually correct. Guyots are submerged, flat-topped seamounts (undersea mountains) that were once volcanic islands. Wave erosion flattened their tops before they subsided below sea level.

**Why the other options are incorrect:**

*   **Option 1: (a), (b) and (c) are correct:** This option is incorrect because statement (c) is false.

*   **Option 2: (a) and (c) are correct:** This option is incorrect because statement (c) is false.

*   **Option 3: only (a) is correct:** This option is incorrect because statement (b) is also true.

**Explanation of why statement (c) is incorrect:**

*   **(c) The average gradient of continental slope in oceans is about 10 degrees:** This statement is incorrect. The average gradient of the continental slope is typically between 4 and 5 degrees, not 10 degrees. While some sections of the continental slope can be steeper, the *average* gradient is significantly less than 10 degrees.

**In summary:**

Statements (a) and (b) are factually accurate descriptions of atolls and guyots, respectively. Statement (c) misrepresents the average gradient of the continental slope. Therefore, only Option 4, which states that (a) and (b) are correct, is the accurate choice.