This is a pretty tough analogy question, which makes it a good example to learn from. I'll discuss my approach. First, we want to understand what Author B is saying in the given sentence. Then, we want to strip it of its specifics, such that we can apply it to a totally unrelated scenario.
Step 1. The phrase "essential prerequisite" is really important here. Basically, the author is saying that without judicial candor, the measures to prevent judicial abuse of power become ineffective. Judicial candor is a requirement for placing restraints on the judiciary. These limits are important, but what good are they without judicial candor?
Step 2. Try to state this reasoning simply and in your own words. Here is mine: "Something is necessary in order for something else to function" or "What good are Thing 2 and Thing 3 without Thing 1?" This sounds like rudimentary language, but it helps me find a good match.
Let's look at C. Judicial candor = accurate data = necessary prerequisite/presumption Limitations = relevance and sufficiency = important measures
Just like limits on the judiciary, relevance and sufficiency are important. Without candor, these limits on the judiciary are ineffective. Without accurate data, relevance and sufficiency don't matter.