In which year did Mahatma Gandhi launch the nationwide Non Cooperation Movement against British rule in India?

Introduction / Context:
The Non Cooperation Movement marked the first mass nationwide campaign under Gandhis leadership, urging Indians to withdraw cooperation from British institutions in a non violent manner. It was a response to events such as the Rowlatt Act and the Jallianwala Bagh massacre. This question seeks the year in which this movement was formally launched.

Given Data / Assumptions:
- The movement is the Non Cooperation Movement under Gandhi.
- It is described as a nationwide struggle against British rule.
- The options list several years from 1880 to 1940.

Concept / Approach:
Historically, the Non Cooperation Movement was launched in 1920 and continued until it was called off after the Chauri Chaura incident in 1922. Other key campaigns such as the Civil Disobedience Movement and Quit India Movement belong to the 1930s and 1940s. The task is to recall the correct decade and associate the movement with 1920.

Step-by-Step Solution:
Step 1: Remember that after World War One, dissatisfaction with British policies grew, especially after the Rowlatt Act and Jallianwala Bagh.
Step 2: Gandhi proposed a Non Cooperation Movement to protest these injustices and the failure to grant meaningful self government.
Step 3: The Indian National Congress approved this programme, and it was launched in 1920.
Step 4: The years 1930 and 1942 are associated with later campaigns such as the Civil Disobedience and Quit India movements, not with Non Cooperation.
Step 5: Therefore, 1920 is the correct year to select.

Verification / Alternative check:
An alternative check is to create a mental timeline of Gandhis major national movements Non Cooperation in 1920, Civil Disobedience around 1930, and Quit India in 1942. Placing Non Cooperation at the beginning of this series confirms that 1920 is the right year and not any of the others.

Why Other Options Are Wrong:
Option a is wrong because 1880 predates Gandhis emergence as a leader in Indian politics and is far too early.
Option b is wrong since 1900 is also too early and does not match the post World War One context of the movement.
Option d is wrong as 1940 is closer to the period of World War Two and the Quit India Movement, not Non Cooperation.
Option e is wrong because 1930 is associated with the Civil Disobedience Movement and the Dandi March, not with Non Cooperation.

Common Pitfalls:
Students sometimes confuse the names and years of the three major mass movements led by Gandhi. Another mistake is to assume that all large Gandhian movements happened close to independence, which pushes answers toward the 1940s. Learning a simple three date sequence makes these factual questions much easier.

Final Answer:
The Non Cooperation Movement was launched in 1920.