Who among the following ancient writers is the author of the work Indica, an important account of India during the Mauryan period?

Introduction / Context:
This question is drawn from ancient Indian history and the sources used to reconstruct it. Indica is the name given to an account of India written by a foreign ambassador who visited the court of Chandragupta Maurya at Pataliputra. Even though the original text is lost, large parts survive through quotations by later Greek and Roman writers. Identifying the author of Indica is a basic factual requirement for many history based examinations.

Given Data / Assumptions:
- The work mentioned is Indica, a descriptive account of India.
- The time period is the Mauryan age, especially the reign of Chandragupta Maurya.
- The options include several historical figures, some Indian and some foreign Megasthenes, Seleucus Nicator, Chanakya, Ashoka Maurya and Pliny the Elder.
- Only one of these is the known author of Indica.

Concept / Approach:
The key concept is the link between Megasthenes and the Mauryan court. Megasthenes was a Greek ambassador sent by Seleucus Nicator to the court of Chandragupta Maurya. During his stay in India he wrote a work describing the geography, society, administration and customs of the country. This work is referred to as Indica. Although some of his descriptions are exaggerated or mythical, Indica remains a vital external source on India in that period. None of the other personalities listed matches this profile as author of Indica.

Step-by-Step Solution:
Step 1: Recall that Indica is associated with a Greek ambassador to the Mauryan court.Step 2: Identify Megasthenes as that ambassador, who lived at Pataliputra and observed Indian society.Step 3: Remember that Seleucus Nicator was the Hellenistic ruler who sent Megasthenes, not the author himself.Step 4: Note that Chanakya and Ashoka were Indian statesmen and rulers, not Greek writers, and Pliny the Elder was a later Roman author who quoted from earlier works.Step 5: Conclude that Megasthenes is the only option that correctly fits as the author of Indica.

Verification / Alternative check:
A quick check is to pair names in your memory. You can remember the pair Seleucus Megasthenes, where Seleucus is the king and Megasthenes is the envoy, and the pair Chandragupta Chanakya, where Chandragupta is the king and Chanakya is the adviser. Indica is clearly linked with the foreign observer in the first pair, not with the Indian ruler or adviser. Textbooks consistently identify Megasthenes by name when discussing Indica, while they only mention other writers such as Pliny as later compilers of information.

Why Other Options Are Wrong:
- Seleucus Nicator: He was the Greek ruler who made a treaty with Chandragupta and sent Megasthenes as his ambassador but he did not write Indica.
- Chanakya: Also known as Kautilya or Vishnugupta, he wrote Arthashastra, a treatise on statecraft, not Indica.
- Ashoka Maurya: As a Mauryan emperor, he left many inscriptions but is not credited with any work titled Indica.
- Pliny the Elder: A Roman author who later used and quoted earlier sources, including possibly Indica, but he was not its original author.

Common Pitfalls:
Students sometimes confuse the roles of Seleucus and Megasthenes, or think that Indica might be an Indian work because it is about India. Another mistake is to mix up Arthashastra and Indica when recalling ancient texts. To avoid this, create clear associations Megasthenes for Indica as an outside view of India, and Chanakya for Arthashastra as an internal manual of governance.

Final Answer:
The work Indica, an important foreign account of India during the Mauryan period, was written by Megasthenes.