Which of the following is recognised as the longest natural urban sea beach in India?

Introduction / Context:
India has a long coastline with many famous beaches. Among them, one beach in particular is widely recognised as the longest natural urban sea beach in the country. This question tests both geographical and tourism-related knowledge by asking you to identify that beach.

Given Data / Assumptions:

• The options are Chapora Beach, Diu Beach, Aksa Beach and Marina Beach.
• The phrase “longest sea beach in India” commonly refers to length along the shoreline.
• The word “urban” suggests that the beach is adjacent to a major city.

Concept / Approach:
Marina Beach in Chennai, Tamil Nadu, is often cited as the longest natural urban beach in India and one of the longest in the world. While there are other long beaches in India, the combination of natural formation, length and urban location makes Marina Beach particularly notable. The approach is to recall this well-known tourist and geographical fact and distinguish Marina from the other beaches listed.

Step-by-Step Solution:
Step 1: Consider which beaches among the options are major urban beaches: Marina Beach is directly adjacent to the city of Chennai. Step 2: Recall that Marina Beach is often described as being about 13 kilometres long, making it one of the longest urban beaches. Step 3: Chapora Beach, Diu Beach and Aksa Beach are popular but relatively smaller and not widely claimed as the longest in India. Step 4: Therefore, Marina Beach matches the description in the question.

Verification / Alternative check:
Tourism guides, geography texts and many general knowledge compilations consistently identify Marina Beach as India's longest natural urban sea beach. While some other beaches may claim different types of records, none of the alternatives offered in the options have the same commonly cited superlative regarding length in an urban setting. This confirms Marina Beach as the correct choice.

Why Other Options Are Wrong:
Chapora Beach: A scenic beach in Goa, known for its beauty but not for being the longest sea beach in India.
Diu Beach: Located in the Union Territory of Diu, famous as a tourist spot, but not the longest by shoreline length.
Aksa Beach: A popular beach near Mumbai, yet much shorter than Marina Beach and not associated with national records.

Common Pitfalls:
Some students may confuse “most famous” with “longest” and choose a beach they have heard about more often in movies or travel blogs. Others might ignore the term “urban” and think only of remote or less developed beaches. Remember that Marina Beach is both long and directly adjacent to a major metropolitan city, which is why it is highlighted in GK resources.

Final Answer:
Therefore, the longest natural urban sea beach in India is Marina Beach.