Choose the most appropriate alternative from the options given below to complete the following sentence:

Despite several ______ the mission succeeded in its attempt to resolve the conflict.

The correct option is B setbacks
Setbacks: Despite several setbacks the mission succeeded in its attempt to resolve the conflict.

The word 'Despite' indicates that there has to be a contrast in the sentence, use of the word 'Setbacks' in the blank indicates that despite many problems the mission was successful.