Thanks for the question! So what’re we told here. We know that decentralization helps autonomous functioning, which always permits more realistic planning and strongly encourages innovation.
Now take a look at (A), which tells us that in large institutions whose divisions don’t function autonomously, planning isn’t maximally realistic. This is pretty strong wording, but it’s supported here. We know that autonomous functioning ALWAYS permits more realistic planning. That means that if you aren’t autonomously functioning, your planning isn’t maximally realistic, because you could function autonomously, which would permit more realistic planning.
(C), on the other hand, is incorrect because the stimulus never talks about the disadvantages of decentralization, so we can’t weigh the advantages against the disadvantages based on the stimulus.
Hope this helps! Feel free to ask any other questions that you might have.