The complicated processes, which often __________ reason, forced us to become very creative in finding ways to work __________ the challenges.

Let us try to infer what the author intends to convey through the sentence.

The meaningless complicated processes forced the author to find methods to skip the processes. 

'Defied' is the correct term to be used in the first blank since the first part should convey that the processes were meaningless. 

Also, work 'around' something means to bypass something. From the sentence, we can infer that the author found a way to skip the complex meaningless processes. Therefore, option C is the right answer.