Nawab Siraj-ud-daulah of Bengal was defeated by the English in the Battle of Plassey mainly due to which of the following reasons?

Introduction / Context:
The Battle of Plassey (1757) is a crucial turning point in Indian history, marking the beginning of British political dominance in Bengal and later in the whole of India. Understanding why Nawab Siraj-ud-daulah was defeated helps you grasp the role of intrigue, diplomacy and betrayal in colonial expansion. Rather than pure military strength, the key factor was the conspiracy orchestrated by Robert Clive and his allies inside the Nawab's camp.

Given Data / Assumptions:

• The question focuses on the main reason for Siraj-ud-daulah's defeat at Plassey.
• We have options mentioning military strength, conspiracy, retirement from the battlefield and the capture of Frenchmen.
• We assume the standard narrative presented in Indian history textbooks.
• The answer sought is the primary, decisive factor, not minor contributory causes.

Concept / Approach:
Although the English East India Company forces were not overwhelmingly stronger in numbers, they had a decisive advantage because of internal treachery in the Nawab's camp. Robert Clive entered into a secret agreement with Mir Jafar, the Nawab's Commander-in-Chief, and influential bankers such as the Jagat Seths. Many of the Nawab's key commanders either withheld their troops or did not fight with full commitment. As a result, Siraj-ud-daulah was effectively isolated in battle even though his army was larger on paper. The conspiracy and betrayal, rather than straightforward military inferiority, were the main reasons for his defeat.

Step-by-Step Solution:
Step 1: Recall that the Battle of Plassey was fought in 1757 between Siraj-ud-daulah and the English under Robert Clive.Step 2: Remember that Mir Jafar, the Commander-in-Chief of the Nawab's army, secretly aligned with the English and did not support Siraj-ud-daulah in battle.Step 3: Note that influential bankers and other courtiers also sided with the English, hoping to profit from a change of regime.Step 4: Realise that this conspiracy meant that large parts of the Nawab's army remained inactive or deliberately ineffective during the battle.Step 5: Therefore, the main reason for defeat was the conspiracy led by Clive in coordination with Mir Jafar and the rich bankers, as stated in option (b).

Verification / Alternative check:
Standard history textbooks and competitive exam guides describe the Battle of Plassey as being won more by 'treachery' and diplomacy than by battlefield heroics. They emphasise the role of Mir Jafar's betrayal and the support of the Jagat Seths, Omichand and others. This is reflected in exam questions where the correct option always highlights the conspiracy and betrayal, not mere numerical strength or minor incidents.

Why Other Options Are Wrong:
The English forces were militarily much stronger: In terms of sheer numbers, the Nawab's army was larger; the English won primarily because of internal betrayal, not overwhelming strength.Siraj-ud-daulah's sudden retirement from the battlefield: While his leadership had weaknesses, this is not cited as the principal explanation in historical analyses.Capture of a band of Frenchmen: The French support was limited, and this incident alone cannot explain the collapse of the Nawab's much larger army in the decisive battle.

Common Pitfalls:
Students sometimes oversimplify historical events by assuming that the side with better weapons or European troops always won. In the case of Plassey, the key issue was not raw military power but political intrigue and betrayal. Another pitfall is ignoring internal divisions within Indian states and attributing everything to 'British superiority'. For exam purposes, you should clearly remember that the conspiracy of Mir Jafar and the bankers, managed by Clive, was the central cause of Siraj-ud-daulah's defeat at Plassey.

Final Answer:
Nawab Siraj-ud-daulah was defeated at Plassey mainly because of Clive's conspiracy with Mir Jafar and the rich bankers of Bengal.