Alexander, the Macedonian ruler commonly known as Alexander the Great, invaded northwestern India in which year before the common era?

Introduction / Context:
Alexander the Great is a central figure in ancient world history, and his expedition to India is a landmark event for both Greek and Indian narratives. Many exam questions ask about the year in which he crossed into the Indian subcontinent and fought battles such as the famous Battle of the Hydaspes. Remembering this date helps place Indian events in a broader world history timeline.

Given Data / Assumptions:

• The question asks for the year of Alexander entry into India.
• The options are different years before the common era, close to one another.
• We assume the standard chronology used in school and competitive exam syllabi.

Concept / Approach:
Historians generally agree that Alexander crossed the Hindu Kush and entered the northwestern frontiers of the Indian subcontinent in 326 BC. His campaign included battles with local rulers such as King Porus near the Hydaspes River. By comparing this known date with the options, you can identify the correct year.

Step-by-Step Solution:
Step 1: Recall that Alexander became king of Macedon around 336 BC. Step 2: Remember that he moved eastward, conquering Persia before reaching India. Step 3: The invasion of India is recorded as taking place in 326 BC. Step 4: Scan the options to find 326 BC. Step 5: Select 326 BC as the correct answer.

Verification / Alternative check:
You can cross check by linking events: Alexander defeat of Darius in Persia and subsequent march towards the Indus valley occur between 331 BC and 326 BC. The Battle of the Hydaspes against King Porus is consistently dated to 326 BC in standard history texts. No other option matches this accepted chronology.

Why Other Options Are Wrong:
Options B, C, D, and E present other years in the same century but do not correspond to Alexander presence in India. 336 BC relates to his accession to the throne, while the earlier dates precede his major eastern campaigns. The year 316 BC is after Alexander death in 323 BC, so he could not have invaded India then.

Common Pitfalls:
Students sometimes confuse 326 BC with 323 BC, the year of Alexander death. Another error is to reverse digits or misread the options because all years look similar. To avoid this, always associate the phrase Alexander invasion of India with the specific year 326 BC.

Final Answer:
Alexander the Great invaded northwestern India in 326 BC.