The question below consists of a set of labelled sentence fragments. Out of the four options given, select the most logical order of the fragments to form a coherent and grammatically correct sentence about the absence of zebra crossings.

Introduction / Context:
This question tests your ability to reorder labelled fragments to form a meaningful and grammatically correct sentence. The sentence is about the absence of zebra crossings and its effect on citizens. You are given three labelled parts A, B, and C, which must follow the introductory phrase so that the final sentence reads smoothly and logically.

Given Data / Assumptions:

• Introductory words: "The absence of zebra".
• Fragment A: "to the life and person".
• Fragment B: "of citizens in most cities".
• Fragment C: "crossings has become a threat".
• Options for order: BCA, BAC, CAB, ACB.
• Intended final idea: The absence of zebra crossings has become a threat to the life and person of citizens in most cities.

Concept / Approach:
To build the sentence, we must first complete the noun phrase that begins with "The absence of zebra". Logically, this should be followed by "crossings has become a threat" to complete the subject and verb, since "zebra crossings" is the standard term. After that, we expect a prepositional phrase of the form "to the life and person of citizens in most cities", which breaks down naturally into A ("to the life and person") followed by B ("of citizens in most cities"). Thus, the correct sequence after "The absence of zebra" is C-A-B.

Step-by-Step Solution:
Step 1: Begin with the given starting phrase: "The absence of zebra ..." Step 2: Identify which fragment can immediately follow "zebra" to complete a common expression. "Crossings has become a threat" (fragment C) pairs perfectly to form "The absence of zebra crossings has become a threat". Step 3: Recognise that we now need to specify the nature of the threat: a threat to whom or to what. Step 4: Notice that fragment A begins with "to the life and person", which is a natural continuation after "has become a threat". Step 5: Attach fragment B, "of citizens in most cities", to complete the prepositional phrase, giving "to the life and person of citizens in most cities". Step 6: Combine all parts: "The absence of zebra crossings has become a threat to the life and person of citizens in most cities." Step 7: Map this sequence to the label order: C first, then A, then B, which is CAB. Select CAB as the correct option.

Verification / Alternative check:
Try the other sequences briefly. If you start with B ("of citizens in most cities"), you get "The absence of zebra of citizens in most cities ..." which is illogical and ungrammatical. Starting with A ("to the life and person") after "The absence of zebra" gives "The absence of zebra to the life and person crossings has become a threat", which is also incorrect. Only C completes the basic structure "The absence of zebra crossings has become a threat", after which A and B naturally extend the idea.

Why Other Options Are Wrong:
BCA and BAC both place fragment B immediately after "zebra", creating "The absence of zebra of citizens in most cities", which makes no sense. ACB puts A after "zebra", which wrongly connects "to the life and person" directly to "zebra" instead of to "has become a threat". None of these scrambled sequences form a coherent, grammatical sentence.

Common Pitfalls:
A common error is to focus on meaning without paying attention to standard collocations like "zebra crossings". Another pitfall is to join fragments solely based on their prepositions, without ensuring that the initial noun phrase and verb are completed correctly. Always start by forming a valid subject-verb structure ("The absence of zebra crossings has become a threat") and then attach additional modifiers where they naturally fit.

Final Answer:
The most logical and grammatically correct order is CAB, giving "The absence of zebra crossings has become a threat to the life and person of citizens in most cities."