Why did the League of Nations' influence weaken during the late 1930s?

The choice is correct because the League of Nations was significantly undermined by its inability to resolve major international conflicts during the late 1930s. The Spanish Civil War (1936-1939) and the Abyssinian Crisis (1935-1936) served as critical tests for the League, and its failure to take effective action in these situations illustrated its weakness and ineffectiveness in maintaining peace. In the case of the Abyssinian Crisis, Italy's invasion of Ethiopia exposed the limitations of the League's authority since it could not enforce sanctions or prevent aggression from a member state. Similarly, during the Spanish Civil War, the League’s lack of intervention allowed for a protracted conflict that further demonstrated its inability to support peace or resolve disputes among nations. This loss of credibility contributed to a decline in the League’s influence as it failed to uphold its founding principles of collective security and conflict resolution. The other options do not accurately reflect the primary reasons for the League's declining influence during that period.