Cloze passage on judicial appointments: fill the blank in therefore, the process of judicial appointment is of ____ importance.

Introduction / Context:
This blank is the second one in the same passage about the judiciary and democracy. The sentence reads therefore, the process of judicial appointment is of blank importance. The context is emphasising how crucial an independent and upright judiciary is for a free democratic country, so the blank must be filled with a word that indicates high significance.

Given Data / Assumptions:

The passage stresses the role of an independent, able, and upright judiciary.
The sentence begins with therefore, which signals a conclusion based on the earlier idea.
The phrase of blank importance usually takes adjectives like great, prime, or vital when the importance is high.

Concept / Approach:
In formal English, of vital importance is a very common expression meaning extremely important or essential. Since the passage connects the quality of the judiciary with the health of a democratic system, it naturally concludes that the process of appointing judges is of vital importance. Other options either do not fit grammatically or convey the wrong degree of importance. Therefore, vital is the best and most idiomatic choice for the blank.

Step-by-Step Solution:
Step 1: Note the logical connector therefore, which indicates that the author is drawing a strong conclusion. Step 2: Understand that if the judiciary is essential for democracy, then how judges are appointed must be very significant. Step 3: Look at the phrase of blank importance and recall that of vital importance is a standard collocation for something extremely important. Step 4: Check whether vital fits smoothly: the process of judicial appointment is of vital importance. Step 5: Eliminate options that either do not form common phrases or contradict the logic of the passage.

Verification / Alternative check:
You can test the alternatives in the sentence. Of mere importance sounds odd because mere is usually used before a noun, as in a mere formality, and even then suggests something small or insignificant. Of social importance changes the meaning and narrows it unnecessarily. Of marginal importance means of little importance, which directly contradicts the thrust of the passage. Only of vital importance carries the strong positive emphasis that matches the tone of the text.

Why Other Options Are Wrong:
Option A mere implies only or just and often downplays importance, which is the opposite of what the author intends here.
Option B mourn is not an adjective and does not fit grammatically in the phrase of mourn importance.
Option C social shifts the focus from importance to a specific type of importance and does not capture the essential, core role of judicial appointments.
Option E marginal suggests something unimportant or on the edge, again conflicting with the central role that judicial appointments play in a democratic system.

Common Pitfalls:
In cloze tests, many distractors sound plausible at first glance but do not match standard collocations. A good exam strategy is to read the entire phrase, not just the single word, and to recall common textbook expressions. Phrases like vital role, vital function, and of vital importance occur frequently in academic writing about constitutions and governance, so they are safe choices when the context stresses essential features.

Final Answer:
The correct completion is of vital importance, so the sentence reads therefore, the process of judicial appointment is of vital importance.